Written by Don DeLoach
Competition has international appeal
Event coverage
Photos by the author except as noted
As seen in the July 2016 issue of Model Aviation.

Twelve individual World Champions in Free Flight were among the approximately 200 international competitors at Lost Hills, California, February 6-14, 2016.

The potpourri of Free Flight, which has come to be known as Fabulous February, is actually six contests in one. It begins with the Issacson Winter Classic, a multifaceted tapestry of Free Flight including AMA and Nostalgia (1950s) events and entry-level events such as P-30 and E-36.

Concurrent with the Issacson Winter Classic weekend is the Kiwi Cup of New Zealand, the first of three FAI World Cups for F1A, F1B, F1C, F1P, and F1Q. On Tuesday there’s another World Cup for F1A, F1B, F1C, F1P, F1Q, and the Pan American Cup of Canada, followed by two World Cups for F1E (Slope Soaring) gliders. The main event on the final Friday through Sunday is the Bob White Max Men International World Cup.

An intense moment-of-release photo of Peter Brocks (USA) launching an F1E model. Furutani photo.

Fabulous February, sometimes called Fab Feb, has become the lengthiest Free Flight gathering in North America and second in total attendance only to the AMA Outdoor Free Flight Nats in Muncie, Indiana.

Former World Champion Matt Gewain (USA) launches an F1C folder aircraft. Photo by Brian Furutani.

The Elites of International Free Flight

Oleg Kulakovsky and Alex Andriukov were at Lost Hills as usual. During the last three decades, the pair has revolutionized the F1B Wakefield Rubber event. They produce models and parts for the world’s top competitors—models they’ve personally used to win seven of the last 12 F1B World Championships. Both are Ukrainian born, and Alex is now a US citizen and a regular competitor at Lost Hills.

The father of the modern F1C model is Eugene Verbitsky, of Ukraine, who is a winner of three individual World Championships (1987, 1993, and 2011). His countryman, Artem Babenko, is a close second in stature, having won two World Championships. Both are elite designers and builders of F1C aircraft used by the world’s best fliers. Roy Summersby is another F1C luminary, having won the individual world title in 2013.

Per Findahl, an enthusiastic two-time F1A world champion, was in attendance from frigid Sweden. Other former F1A world champions spanning three decades included Mike McKeever (USA), Stepan Stefanchuk (Ukraine), Matt Gewain (USA), Mikhail Kochkarev (Russia), Mike Fantham (Great Britain), and Sergey Makarov (Russia). It might as well be called Famous February.

Mike Roberts (USA) launches in F1C. Furutani photo.

The Throwback Events

Undoubtedly, the best feature of Fab Feb is that it has evolved into a melting pot of Free Flight eras and disciplines. One-hundred-plus high-tech sportsmen from more than 30 nations share the field with some of America’s best traditional modelers, flying classic balsa designs such as Gollywocks and Stardusters. No other Free Flight gathering on the planet mixes the two worlds on such a grand scale.

There’s a full complement of National Free Flight Society (NFFS) Nostalgia events, AMA Gas, Rubber, and Glider, and even Society of Antique Modelers (SAM) Old-Timer events. A glider pen is set up and both AMA and Catapult Glider contests are held each day—one for National Cup points and one for cash prizes (the Human Powered World Championship Awards, sponsored by the family of the late Paul MacCready).

There are mass launches for special events such as E-36, E-20, and Gollywock. Perpetual trophies are awarded for Nostalgia Wakefield, Gollywock, F1A, F1B, and F1C.

The Electric Revolution

The year 2016 marked the beginning of the F1S event, and Fab Feb featured the second and third contests of this highly anticipated gathering. F1S is identical to AMA E-36, except for the five-round format and the standard motor run set at 10 seconds. The afternoon flyoff for F1S at the Kiwi Cup provided some excellent drama in tricky lift conditions. Dick Ivers (USA) took the top spot as the only flier able to max on the 5-second flyoff run.

Three years ago, I created the first E-36 World Open Championship, featuring a unique format of the AMA event, plus a single-flight evening mass launch, totaled into a single, factored score. This year, the World Open was generously sponsored by CB Model Designs and Bill Vanderbeek. The very deserving 2016 World Open Champion is Derek McGuckin from the state of Washington.

Dick Ivers readies his F1Q model for the Kiwi Cup flyoff. Dick won the F1S event the following day.

Special Memories

It was widely agreed that it was the best weather ever for Lost Hills in February. It was simply outstanding-to-perfect the entire eight days. The many international sportsmen were not at any disadvantage having to retrieve on foot, and much test-flying was accomplished during the downtime between contests.

Ronnie Espolt, an RC flier from California, attended his first Fab Feb in 2016. Furutani photo.

California fliers Jim Parker, Roger Morell, and Mike McKeever spearheaded a build-and-fly event for local Lost Hills kids during the Isaacson competition. It was an inspiring sight to watch these elite fliers donate an entire day of personal flying time to help these youngsters, many of whom enjoyed excellent flights with their
catapult gliders.

The worst hard-luck story was Reinhard Truppe, an F1C flier from Austria, who suffered a baggage-handling nightmare. His model box had its end broken off, and clearly some model parts fell out and were sloppily stuffed back in. It must have fallen from a great height or it had been run over.

All of Reinhard’s models were severely damaged. He missed the Kiwi Cup, but with the help of his entourage and Artem Babenko (Ukraine), he was able to fly in the other events, collecting one podium place.

The unofficial Iron Man award went to Christian Andrist, from Switzerland, who towed his F1A up a steep 40-meter hill during the Max Men 6-minute flyoff. This was a high-risk, high-reward activity. He could have easily lost control of the F1A during the tow or become caught in a crosswind, but it paid off. He made the 6 minutes and came out on the podium in the 10-minute morning flyoff, finishing ahead of a number of accomplished sportsmen.

On the last day of the week, Janna Van Nest performed a flightline wedding ceremony for longtime F1B man Dick Meyers, and Betty Davis. Janna is authorized to perform weddings in California.

Janna was the main organizer for the Ladies Tea Party, which was a great success. She also coordinated with Gabby’s Grill & Cafe to make sure the food truck got the best place on the field.

It was good to see that Peter Allnutt (Canada) hasn’t lost his gallantry. He provided Valentine’s Day roses for all of the women!

Finally, there was little question about who the top flier was this Fab Feb. Australian Roy Summersby won the F1C event in all three World Cups—an astounding feat!

This year, Lee Hines finished second to Englishman Phil Ball (R) who had a 76-second final flight.

Larissa Savukhina (Russia) was the sole female entrant in F1C. She was consistently competitive, finishing third in the Kiwi Cup. Photo by Brian Furutani.

Wrapping Up

If you are even a casual fan of Free Flight and/or international air sports competition, you should make plans to attend Fabulous February. The anticipated dates for the 2017 gathering are February 11-19. Nowhere else in the world will you experience so many modeling cultures and differing languages on a common flightline with such outstanding fellowship.

Free Flight forever!

Maxes and Flyoffs

Major FAI Free Flight contests are scored based on the total time accrued throughout seven (sometimes five or three) individual flights. Each flight has a maximum target time, or “max” for short. Excess flight duration beyond the max is not counted.

The events F1A, F1B, F1C, F1E, F1P, and F1Q stipulate the seven individual flights to be flown in one-hour rounds, with a standard max of 3 minutes. In the event of ties at the end of the seven rounds of regulation flying, a sudden-death, head-to-head “flyoff” (think overtime in football) is held. Flyoffs feature extended maxes (5 to 10 minutes) and shortened launch windows of only 10 minutes. This is when the pulse-pounding drama of Free Flight is revealed.

International Free Flight Events

F1A: These are Towline Gliders with a total area of between 32 and 34 square decimeters (496 to 527 square inches), and 410 grams (14.46 ounces) minimum weight. There is a 50-meter maximum towline length. F1A includes a World Championship and World Cup event for Juniors and Seniors.

F1B: This is an event for rubber-powered Wakefield models with a total area of 17 to 19 square decimeters (263.5 to 294.5 square inches), 200 grams (7.07 ounces) minimum empty weight, and 30 grams maximum rubber weight. It includes a World Championship and World Cup competition for Juniors and Seniors.

F1C: These are glow-powered, alcohol-fueled models of approximately 600 square inches, with a maximum power loading of 300 grams per cc (10.58 ounces per cc), powered by up to 2.5cc (.15 cubic inch) engines on a 4-second maximum engine run. It includes a World Championship and World Cup event for Seniors.

F1E: These magnetically steered Slope Soaring gliders have a maximum area of 150 square decimeters (2,325 square inches) and a maximum flying weight of 5 kilograms (176.37 ounces). The event includes a World Championship and World Cup competition for Seniors.

F1Q: This event is for electric-powered models of approximately 400 square inches weighing 15 ounces. Motor-run time is based on a maximum of 5 joules allowed per gram of total weight. It is a World Cup event for Seniors.

F1H: F1H is for small towline gliders with a maximum area of 18 square decimeters (279 square inches) and a minimum model weight of 220 grams. There is a maximum towline length of 50 meters.

F1G: Models in this category are small, rubber-powered Coupe d’Hiver aircraft. The minimum model weight is 70 grams empty. The maximum rubber weight is 10 grams.

F1J: This category is for small, glow-powered models with 1cc (.061 cubic inch) maximum displacement. The minimum weight is 160 grams (5.63 ounces), with a maximum engine run of 5 seconds. There are no fuel restrictions.

F1S: This is the new small-electric class. Models must be powered by two or fewer LiPo battery cells (7.4 volts maximum). The model must weigh a minimum of 120 grams, with a projected wingspan maximum
of 36 inches (92.30 centimeters).

—Don DeLoach
ddeloach@comcast.net

Additional photos

Sources

NFFS
www.freeflight.org

FAI Free Flight events
www.fai.org/ciam-our-sport/f1-free-flight

SAM
www.antiquemodeler.org

AMA Nats
www.modelaircraft.org/events/nats.aspx

CB Model Designs
cbmodeldesigns@yahoo.com
www.cbmodeldesigns.com

Written by Jon Barnes
Take your foam jet experience to the next level
Product review
Photos by the author
Read the full product review in the July 2016 issue of Model Aviation.

Specifications

• Model type: EDF jet
• Skill level: Intermediate to advanced
• Wingspan: 44.8 inches
• Wing area: 512 square inches
• Length: 56 inches
• Weight: 129 ounces
• Power system: 90mm electric ducted fan
• Radio: Minimum seven-channel radio/receiver
• Construction: EPO foam
• Street price: $499

Test-model details

• Motor used: Freewing 3748-1550 Kv brushless outrunner (installed)
• Speed controller: Freewing 130-amp brushless with separate 8-amp BEC (installed)
• Battery: Admiral 6S 22.2-volt 5,000 mAh 50C LiPo with EC5 connector
• EDF: Freewing 90mm with 12-blade impeller (installed)
• Radio system: Spektrum Black Edition DX9 DSMX 2.4 GHz transmitter; Spektrum AR8000 DSMX receiver
• Ready-to-fly weight: 129 ounces
• Flight duration: 3 to 4 minutes

Pluses

• Extremely high level of scale detail.
• High blade count impeller produces excellent thrust, with accompanying realistic-sounding and ear-pleasing acoustics.
• CNC aluminum suspension-equipped struts and sequenced, multipanel gear doors.
• Operational speed brakes and LE slats.
• Multipin wing connectors and wiring interface module help to tame the abundance of wiring.

Minus

• Relatively short flight duration.

Product review

Pilots who love flying foam-composition scale jets have, in the past, been forced to make a few obligatory concessions. Until recently, most mass-produced jet models typically featured a meager level of scale detail. Additionally, the electric ducted-fan (EDF) power systems included with many of the kits of yore were underpowered, out of balance, and obnoxiously noisy.

Pilots who preferred any higher level of scale detail and/or a more powerful, better-sounding EDF power system were forced to spend countless hours engineering and improving their jet models. Although that process might be the best part of the hobby to a select few, most prospective EDF jet fliers probably prefer that a model come out of the box already equipped with an impressive level of scale detail and a smooth, appropriately powerful EDF power system preinstalled. Motion RC recently released a series of Freewing Super Scale 90mm EDF jets that are sure to please EDF-loving pilots interested in a scale jet model.

The first kit to be released in the series was the popular T-45 Goshawk. The McDonnell Douglas T-45 Goshawk made its first flight in 1988. This carrier-capable aircraft has since been used extensively by the U.S. Navy and Marine Corps as a jet flight trainer.

There have been more than a few T-45 kits available to modelers throughout the last few years, most of them done up in the trademark U.S. Navy International orange and white color scheme. Model pilots prone to protest the arrival of “yet another orange and white USN Goshawk” were stopped midsentence by the impressive list of features included with this 90mm EPO foam-composition EDF jet.

Freewing’s 90mm EDF-powered version of the U.S. Navy-themed T-45 Goshawk is stunningly detailed.

The T-45 is available in Plug and Play (PNP) and ARF Plus variants. The former includes all electronic components, while the latter omits the EDF unit and speed controller. The ARF Plus kit is perfect for pilots who prefer to source their own power system. The availability of this option does not infer that the 90mm EDF that Freewing installs in the PNP version is in any way a lackluster performer. To the contrary, this high-performance 90mm EDF uses a 12-blade impeller and endows the T-45 with plenty of thrust!

The long list of scale-enhancing features included with this exquisitely detailed jet is guaranteed to fog the face masks of even the most jaded jet pilots. This model uses worm-gear-driven leading edge (LE) slats. To my knowledge, it is the first time that this unique and fully functional feature has ever been included on a mass-produced model!

Sequenced, multipanel gear doors and trailing link suspension-equipped electric landing gear nicely replicate the geometry and functionality of the full-scale Goshawk’s tricycle landing gear. Rows of plastic vortex generators are positioned slightly aft of the wing’s LEs. Other cool plastic details include a tailhook, functional speed brakes, a pitot tube, and antennae.

A removable cockpit and hatch includes a pair of pilot figures and a nicely detailed cockpit interior. The clear plastic canopy even mimics the explosive cord used to predetonate the full-scale T-45’s canopy milliseconds before the pilots’ ejection seats will fire.

A full array of strobing and fixed navigation lights comes preinstalled, as does a small wiring interface module that helps to manage the abundance of wiring used on this full-featured model.

Finally, Freewing did not simply add a few details to the wings and white stabilizers and call it a U.S. Navy scheme. The impressive number and variety of factory-applied maintenance graphics and U.S. Navy markings adorning every inch of this big Goshawk jet help it live up to its Super Scale moniker!

Assembly

The PNP version of the T-45 comes out of the box in such an advanced state of completion that there is no need to spend hours at one’s workbench assembling and prepping this detailed jet for its first flights. Pilots pulling the parts out of the box for the first time can instead use the time to savor the incredible variety of included scale details!

The only items that pilots will need to source to get this quick-assembling PNP kit in the air are a seven- to nine-channel receiver and a 6S 50C 5,000 mAh LiPo battery.

An abundance of plastic bits are used to enhance the scale outline of the Goshawk. Notable pieces include a striped tailhook and detailed cockpit with twin pilot figures. The cockpit instrumentation even includes a simulated lighted heads-up display!

Freewing supplements the air supplied to the preinstalled 90mm EDF power system through the scale twin inlet ducts with a large auxiliary air inlet opening, located on the bottom of the fuselage just forward of the fan assembly. A large, rectangular, plastic, louvered inlet panel helps to prohibit the entry of potentially damaging foreign objects and debris.

Best practices when assembling a PNP configuration kit include taking a little time to inspect the integrity of all of the control surface hinges and pushrod connections. Freewing’s use of ball-link-style connectors on the control surface side of the pushrods comes with the advantage of minimal backlash. This can help a model respond more crisply to control inputs and track more precisely in the air and on the ground.

Actual assembly of the airframe involves mounting the horizontal and vertical stabilizer assemblies and two-piece wing. Removable fasteners allow pilots to easily break the model down for transport or replace damaged components when necessary. A little adhesive is required to mount the two different tail cone pieces and to attach the nose cone-mounted pitot tube.

The entire nose cone assembly itself is conveniently engineered to be easily removable and is held in place using magnets. This helps prevent damage to the somewhat delicate component by popping it off for transport and storage. The two wing halves utilize multipin connectors. These conveniently aggregate all of the electronics used in each wing half onto one larger connector. This simplifies wing attachment and removal, and reduces the chances of making wrong connections when assembling the model at the field.

Pilots who want to have independent control of all of the T-45’s features will need to source a minimum eight-channel receiver. A seven-channel receiver can alternately be pressed into service, although this option will require that the slats and flaps are connected to, and driven by, the same channel.

As a longtime Spektrum radio system user, the form factor and number of channels offered by the Spektrum AR8000 DSMX eight-channel receiver made it the obvious choice for this high-performance jet. This full-range receiver’s use of a satellite receiver, which brings the added benefit of multipath redundancy, gives pilots an extra level of confidence. The length of the satellite receiver’s pigtail allowed it to be located forward of the main receiver, near the nose gear retract mechanism.

The black and white assembly manual offers in-depth assembly and component replacement instructions. It includes a complete listing of the 14 servos preinstalled in the airframe, as well as their rotation and the lengths of their leads.

A detailed printout and mapping of the included E04 wiring module assists pilots with the connection of all of the various lights and servo leads. The manual also recommends high- and low-rate throws, the proper center of gravity (CG) location, and that pilots configure the elevator’s neutral position to be slightly biased toward the down position.

This full-featured T-45 includes an abundance of radio connections and wiring; Freewing’s use of the E04 Integrated Circuit Module helps keep it all as neat as possible.

Although the recommended six-cell 22.2-volt 5,000 mAh LiPo battery fits snugly into the battery bay, enough room exists to move it forward and aft for the optimum CG. Those who prefer to source their own high-performance 8S or even 10S EDF power system will want to opt for the ARF Plus version of this kit. The sole difference is that this kit omits the stock Freewing 90mm power system. All other electronics come included and preinstalled exactly as they do in the PNP version.

Flying

The importance of performing a thorough preflight routine is imperative. This helps to minimize any in-flight surprises—something most pilots prefer to avoid when flying a larger, high-performance EDF jet model such as the T-45.
Positioning the big Admiral six-cell 5,000 mAh LiPo battery so that its forward edge is even with the Goshawk’s twin intakes balances the airframe within a few millimeters of the recommended CG. The assembly manual recommended a takeoff configuration of half flaps to allow the T-45 to rotate sooner than when takeoffs are performed without the flaps deployed. Whatever takeoff flap configuration a pilot elects to use, the airframe needs time to accelerate to a proper rotation speed.

Although the thrust produced by the Freewing 90mm EDF motivates this 8-pound jet hastily forward, the sound produced by the 12-blade impeller at full throttle is a guaranteed grin generator!

The aluminum trailing link tricycle landing gear nicely absorbs aberrations in the runway surface and helps to keep this jet tracking nicely in the takeoff roll. Only minimal rudder corrections are typically required.

Scale EDF jets fly best when operated in a scalelike manner. The higher wing loading of this airframe precludes pilots yanking and banking it around in the same manner that they would a lightly loaded sport jet. The throttle should generally be kept above 50% at all times and turns should be kept on the gradual side; however, these statements are not intended to infer that this model is difficult to fly.

Keep the speed up and the transmitter inputs controlled and deliberate and the Freewing T-45 will happily cruise around the sky without any bad behavior. High-rate control authority gives a pilot the ability to loop and roll this T-45 with only modest amounts of stick movement required.

The extreme level of out-of-the-box scale detailing, combined with the incredibly smooth, turbine-like sound of the Freewing 90mm EDF power system, give this jet an in-flight appearance and presence that surpasses any EDF model I have experienced!

Freewing’s 12-blade 90mm EDF power system make this jet sound as good as it looks.

The impressive performance offered by this 90mm EDF jet comes with one caveat: typical flight durations using the stock Freewing six-cell 90mm EDF power system will be in the range of three to four minutes.

Although many pilots use a countdown timer to alert them to the need to land, this model is the perfect candidate for the use of a radio telemetry system. Receiving real-time feedback about the voltage of the flight battery enables a pilot to maximize the flight durations of this high-performance model and minimize any chance of accidentally flying this jet into a low-voltage cutoff condition.

Most pilots will agree that the landing is what separates the men from the boys. Freewing’s use of LE and speed brakes on the Goshawk give pilots additional resources that can help bring this big jet safely home every time.

The best landing approaches will occur if pilots give this model a little time to adjust to each applied change in configuration. Quickly and simultaneously dumping flaps, gear, slats and speed brakes can potentially upset the airframe and get a pilot into trouble.

Performing a controlled and traditional rectangular landing approach, with nice extended legs and gradual, arcing transitions through the corners, is a recipe for the perfect, scalelike landing. Well-planned deployment of each individual piece of the airframe should be a pilot’s goal when shooting an approach.

An upwind pass directly over the runway centerline is a great way to visually verify that a pilot has all three landing gear down. The first notch of flaps can be deployed with the jet turning crosswind to downwind. Using a transmitter’s flap speed setting to substantially slow the movement of the flaps allows the jet to settle into the new configuration with minimal pitch changes. Full flaps and slats can be deployed on either the crosswind leg or the base leg.

As the airframe gets “dirty,” pilots will need to actively modulate the throttle to maintain airspeed. Fly the T-45 all the way into the numbers and it can execute the prettiest, nose-high landing approach imaginable!

The suspension-equipped aluminum trailing link landing gear helps the Goshawk “stick” to the runway when landing.

Pilot preference will dictate whether the speed brakes are deployed on final approach or during the landing rollout. The sight of this superbly scalelike model on final, with its nose gear mounted and super bright landing light ablaze, will send a shiver of excitement down the spine of pilots and onlookers alike.

Conclusion

With the availability of this amazingly detailed EPO foam-composition jet, pilots can now buy a turnkey, scale, high-performance military jet at a price point that most hardcore EDF enthusiasts will find perfectly palatable. The included six-cell Freewing 90mm EDF power system amply powers the T-45 to roughly 80 to 85 mph and produces smooth, somewhat turbinelike acoustics that are sure to be a sweet-sounding symphony to the ears of EDF enthusiasts.

Pilots who like to go fast know that speed costs money. Or, in the case of this model, speed comes at the expense of amp draw.

With shorter-than-normal flight durations, which is the sole caveat of this exquisitely detailed PNP kit, pilots who crave a large, highly detailed, and superbly performing scale military jet will assuredly love the way this model looks, sounds, and performs in the air!

—Jon Barnes
barnesjonr@yahoo.com

Bonus video

Manufacturer/Distributor

Freewing/Motion RC
(224) 633-9090
www.motionrc.com

Sources

Spektrum
(800) 338-4639
www.spektrumrc.com

Immerse yourself in the action and earn extra money while you're here!

Are you attending the 2016 Outdoor Nats? Do you want to immerse yourself in the action while having the opportunity to make between $50 and $100 per day?

Consider joining the NatsNews staff as an event reporter!

Open positions available include:
• RC Scale Aerobatics (July 5- 8) (This position has been filled.)
• Control Line Navy Carrier (July 19-21)
• Several events in RC Soaring (July 23-July 30)
• Outdoor Free Flight (July 25-29).

Interested? Email us!

If you are interested or would like more information, please email natsnews@modelaircraft.org.

Written by Terry Dunn
A low-cost, multipurpose quadcopter
Product review
Photos by the author
As seen in the July 2016 issue of Model Aviation.

Specifications

• Model type: RTF utility quadcopter
• Size: 19.7 inches (500mm)
• Weight: 42.3 ounces (2.64 pounds) without payload
• Radio system: Tactic TTX810 eight-channel 2.4 GHz transmitter; TR825 receiver (included)
• Power system: Four outrunner brushless motors; 12 x 4.5 propellers; 10-amp ESCs; FlightPower 3S 5,000 mAh 25C LiPo battery; Duratrax Li-24 charger (all included)
• Needed to complete: Four AA batteries for the transmitter
• Minimum flying area: Club field
• Duration: 11 minutes without payload
• Price: $299.99

Pluses

• Adjustable flight performance.
• Mounting rails accommodate various payloads.
• Small footprint with folding arms.

Minuses

• Engages automatic RTH before there is a low-battery warning.
• Loose battery-mounting system.

Abridged Product review

Helimax calls the FORM500 a utility drone. Instead of being designed with a specific purpose, this quadcopter can adapt to accomplish all sorts of functions. Its powerful rotor system can haul up to 2 pounds of payload, and its rigid rail system provides easy mounting options for different accessories.

In the Box

The FORM500 is sold as an RTF package. It includes a fully assembled airframe, an eight-channel Tactic radio system, and a 5,000 mAh LiPo battery with a charger. You only need to add four AA-size batteries for the transmitter.

The Helimax FORM500 RTF package includes a fully built quadcopter, a radio, a battery, and a charger.

Flight Preparation

The flight controller has two flight modes: Stabilize and Position Hold. In Stabilize, the quadcopter will self-level when you release the control sticks. Position Hold also has self-leveling capabilities, but it uses GPS to keep the FORM500 in place when you are not providing control inputs. It will hover in one spot despite any wind that tries to take it away.

The flight mode is selected via a three-position switch on the transmitter. The third position on the switch is for Return-to-Home (RTH). Activating this feature autonomously brings the FORM500 back to land at its original takeoff location.

Headless Mode is a feature that makes all of the control inputs relative to your location, instead of the orientation of the FORM500. Pushing forward on the right control stick in normal control mode (Altitude Hold), for instance, will make the quadcopter translate in whatever direction its nose is pointing.

In Headless Mode, pushing the right stick forward will cause the FORM500 to translate away from you, regardless of which way the quadcopter’s nose is pointing. Headless Mode can be a useful safety net if you lose in-flight visual orientation of the aircraft.

It is important to calibrate the sensor and compass before your first flight. I made sure to complete these steps as outlined in the manual, and I balanced the self-tightening propellers before installing them on the motors.

The onboard electronics are arranged in an uncluttered layout and all of the components are easily accessible.

The frame arms can be folded for easier storage and transport.

Flying the FORM500

I didn’t have any trouble flying the FORM500. It responded well to control inputs and was stable in a hands-off hover. The Tactic TTX810 transmitter has one dual-rate switch that affects pitch, roll, and yaw authority. The high and low rates are preset to 100% and 60%, respectively, and cannot be adjusted, but I think these values work well for the FORM500.

The quadcopter is docile on low rates. High rates provide a hint of speed and aggressive maneuverability. It might not have enough agility to satisfy sport fliers looking for a thrill, but remember that the FORM500 is a “utility drone,” not a “sport drone.”

The quadcopter includes a USB interface cable that allows you to configure the flight controller via a downloadable PC program. The manual does a good job of explaining the effect of changing each of the parameters. I’m still experimenting to get the controller tuned the way that I like it, but I’m enjoying the process.

Without any payload attached, I have achieved flight times of approximately 11 minutes. That duration decreases as you add weight to the FORM500 with attachments.

The quadcopter automatically goes into RTH mode when the battery reaches its low-voltage threshold (as defined in the PC program). This happens without warning, and there is no way to disengage after the automatic RTH begins.

To help prevent this situation, I attached a small, independent battery alarm that connects to the battery’s balance plug. It is set to sound at a higher voltage than the RTH trigger, giving me plenty of warning so I can end the flight normally.

Helimax provides a USB cable and a PC program to adjust the FORM500’s flight controller to a pilot’s preferences.

A removable tray makes battery swaps easy, but there is some play in the latch mechanism.

Conclusion

Similar to many jacks-of-all-trade aircraft, the Helimax FORM500 doesn’t excel at any particular task, yet it does many things well. If you’ve considered getting onboard the multirotor craze, but aren’t sure how you would want to use the aircraft, this quadcopter gives you options. Not only is it available at a low price for an RTF system, but it provides a variety of ways to configure its capabilities and flight performance to your needs.

—Terry Dunn
terrydunn74@gmail.com

Bonus video

Manufacturer/Distributor

Helimax
(217) 398-8970, option 6
www.helimaxrc.com

Hobbico
(800) 637-7660
www.hobbico.com

Sources

FlightPower
(888) 598-8037
www.flightpowerbatteries.com

GoPro
(888) 600-4659
www.gopro.com

RC Logger
support@rclogger.com
www.rclogger.com

RunCam
run@runcam.com
www.runcam.com

Written by Ryan Ramsey
Fly this aviation icon with AS3X as your copilot
Product review
Photos by the author
As seen in the July 2016 issue of Model Aviation.

Specifications

• Model type: BNF
• Skill level: Intermediate
• Wingspan: 48 inches
• Flying weight: 53.9 ounces
• Length: 42 inches
• Radio: Minimum six-channel 2.4 GHz with Spektrum DSM2/DSMX technology and adjustable dual rates
• Flight battery: 3S 2,200 mAh 30C LiPo
• Power system: BL15 850 Kv brushless outrunner motor with 40-amp ESC
• Receiver: Spektrum AR636A six-channel sport receiver
• Price: $269.99

Pluses

• Constructed from durable Z-Foam.
• Removable battery tray and drop tanks.
• Highly visible invasion stripes and paint scheme.
• 15-size BL motor with 40-amp ESC installed.
• Scale four-blade propeller.
• Quick assembly.
• Uses common 3S 2,200 30C LiPo battery.
• Steerable tail wheel.
• Preinstalled flaps and retracts.

Minuses

• Battery tray placement makes it hard to move the CG without adding ballast.
• Airplane feels nose-heavy with the battery all the way aft on the tray. It makes high-rate elevator a better choice while on the ground.

Product review

The Horizon Hobby E-flite P-51D is not just another Mustang. Modeled after the U.S. Army Air Corps 334th Fighter Squadron, this Mustang is determined to please. Intermediate pilots will have no trouble flying this Mustang.

The 48-inch aircraft has a potent 15-size 850 Kv brushless outrunner motor with 40-amp ESC that runs on a 2,200 mAh three-cell LiPo battery. Easily removed external drop tanks, factory installed flaps and retracts, and an AR636A Spektrum receiver with AS3X stabilization are a few of the features that adorn this superb flying model.

The four-blade propeller, painted pilot figure, invasion stripes, and well-dressed landing gear legs and strut covers help set it apart.

The low parts count and well-fitting parts make assembly a breeze.

Assembly

The low parts count and highly detailed, “to-the-point” manual make assembly and setup an easy task. Transmitter setup is the first action laid out in the manual. The P-51D BNF Basic is designed with Spektrum technology. A table in the manual guides you through setups for Spektrum transmitters ranging from the DX6i to DX18.

I like how the table is split. Many of the radios share the same setup, so newer transmitters are grouped together. The DX6, DX7, DX9, DX10t, and the DX18 all share the same setup. DX7s and DX8 also share a setup. Last, but not least, is the DX6i, which stands alone.

This takes the guesswork out of the transmitter setup. Not only does it solve the mystery, it ensures that a pilot—no matter which Spektrum transmitter he or she uses—reaps the benefit of the AS3X system.

AS3X stands for Artificial Stabilization—3 aXis. This allows airplanes to fly similar to a larger, professionally set-up model. The effects of wind and buffeting are dampened and you’ll find that flying on a windy day is easier than it used to be.

The horizontal stabilizer installation is the next step in the manual. The spar goes in first, and the two stabilizer halves simply slide in over it. The root of each stabilizer half fits snugly in a hard, plastic fillet and they key into each other for the moving elevator surface. Two short screws—one on each half—anchor the horizontal stabilizer into the fillet. Attaching the clevis to the recommended outer hole of the elevator control horn finishes the tail section. All other clevises are factory installed and attached.

Moving on to the wing, the Y connectors needed for the aileron, flaps, and landing gear are included in a parts bag. Plugging in the Y connectors to their prelabeled servo leads while noting correct polarity is easier with the wing apart from the fuselage.

Feeding the wires up through the fuselage and toward the receiver is next. Gently pull the wires through while installing the wing. Make sure the wing fits in such a way that the fuselage saddle is unobstructed. When the wing is down and fitting snugly with no servo leads pinched, it is time to secure the wing with the four long machine screws.

After the wing is attached, plug the servo leads into their prospective channels on the AR636A Spektrum receiver. The ailerons must be plugged into the Aileron #2 channel for the AS3X to properly work. Now you can check the control surface directions.

With the propeller still off of the airplane, throttle up to 25% and then lower the throttle to engage the AS3X stabilization system to test it. You can reference the table in the manual to ensure everything is correct. I have flown many AS3X-equipped aircraft and they were always spot on out of the box, but it is important to check.

The propeller installation is the next step illustrated in the manual, but I think that binding the airplane with the propeller off of the model is best to do next. Plus, you can extend the scalelike landing gear and get the aircraft sitting on its gear to finish the assembly.

As I mentioned earlier, setting up the transmitter is one of the first steps. Setting failsafe by rebinding the aircraft after the initial setup is always a good idea. You might find that after binding the receiver with the manual settings, your flaps are not at a perfect neutral position.

Simply return to the Flap System screen on your transmitter and adjust the numerical values to give you the desired flap position. The values might differ slightly from the manual callouts. At this point, rebinding to set the failsafe is a good idea. It ensures that the receiver remembers the proper neutral settings in case of a signal loss.

I’m using a DX6, which allows me to set the flap deployment as a two-second operation. Voice alerts add a cool factor as well. It’s pretty neat to have the radio tell me things such as gear down, flaps up, and time expired.

Now that the system setup is complete, installing the propeller assembly is the next order of business. The spinner backplate goes on first. It fits nicely on the base of the preinstalled propeller shaft, followed by the one-piece four-blade propeller, then the barrel nut. The round barrel nut can be tightened with a small screwdriver. The spinner is screwed in with one screw.

The included external drop tanks simply slide onto rails molded into the wing. The antenna mast is installed aft of the cockpit simply by inserting it in the slot made for it. Now step back and take a look at an excellent flying replica of the iconic P-51D Mustang.

The drop tanks easily slide on and off with rails. The wing-mounted .50-caliber machine guns are molded in plastic.

Preflight

At this point, the model is ready to fly for the first time. When inserting the flight battery on the removable sliding tray, make sure that you hear and feel a click indicating that the tray is all of the way in and secure. Set the airplane on something stationary and plug in the flight battery, while being mindful not to move the aircraft for at least five seconds while the AS3X system gets its bearings.

Flying the E-flite P-51D is awesome. After setting my timer to five minutes for the first flights, per the manual, I’m ready to take to the skies. My center of gravity (CG) is slightly nose-heavy with my battery all the way back on the tray, but it is still in an acceptable range.

A removable battery tray allows for spot-on placement every time.

The battery and its tray slide into the nose where hands can’t reach. Super cool!

The manual suggests taking off in low rate and landing in high. I decided to take off in high rate as well, to help keep the tail planted. For pilots with less stick time, taking off in low rate is a good idea. This helps ensure that sufficient speed is present before takeoff.

Facing into the wind, I hold elevator back pressure and slowly increase throttle. When I have established forward momentum, I gently release my elevator back pressure and let the tail rise. After building up speed, I add in more back pressure and the P-51D is off of the ground.

When I clear the runway, I flip the gear switch and the landing gear tucks away. The next order of business is to climb to a safe height and do any necessary trimming.

Trim the airplane for cruise speed at 3/4 throttle while at a good height, and give no inputs for three seconds. This allows the AS3X system to properly work. Now that that’s done, it is time to explore the flight envelope of this fantastic-looking model.

After extending the flaps and making a nice, slow pass, it was time to wring it out. I like how the AS3X stabilization system helps the airplane feel larger and expertly tuned.

After extending and raising the flaps, I noticed no pitch change. Often, a pilot must play with mixes to negate the pitch effect when deploying flaps, but not with this aircraft!

A full range of warbird aerobatics is the next order of business. Slow rolls, Cuban 8s, wingovers, and inverted flight are all easily achieved with this P-51. Not only can it perform—it looks good while doing it. The easily removed external tanks, along with the antenna mast, add to the scale realism when the airplane is flying by.

The P-51D handles well in its landing configuration. With the landing gear down and flaps deployed, the Mustang really slows down.

It’s a good idea to make a nice, slow pass to get a feel for the airplane’s slow flight characteristics. In my experience, Mustangs like a good two-wheel landing. This ensures that sufficient speed is present—allowing the control surfaces to be effective.

If the model gets too slow upon landing, you might see an ugly bounce. I treat my landings similar to a touch-and-go, which serves me well. With my first approach, I planned to shoot a touch-and-go. I noticed that the airplane settled in nicely. I kept idle at 1/4 throttle to prevent my descent angle from becoming too steep.

After achieving a nice descent angle, I gently flared the airplane and watched it touch down on the main landing gear. I slowly fed the throttle back in and watched the Mustang drive down the runway on two wheels with its tail up. I added a little back pressure and it was off again.

The next approach was the final one. I touched down on the mains, backed off of the throttle, and when the tail started to lower, I planted it to give my rudder steering some authority. Wait to pin the tail until you know the aircraft has bled off enough speed that it won’t take to the air again.

Conclusion

The E-flite P-51D Mustang is a great addition to Horizon Hobby’s 1,200mm-size warbird line. The company provides a nice-size aircraft that runs on a common 2,200 3S LiPo battery power system—making it widely accessible.

The AS3X system makes it a good choice to take to the field when other airplanes might be grounded. The E-flite P-51D has a stable and wide flight envelope that make it predictable in a mellow cruise, as well as being rock solid while being wrung out.

Its highly visible invasion stripes and red nose and tail make orientation easy. The E-flite P-51D is an all-around fantastic airplane that looks as good in the air as it does on the ground.
—Ryan Ramsey
rcairtrainingcommand1@gmail.com

Manufacturer/Distributor

Horizon Hobby
(800) 338-4639
www.e-fliterc.com

Sources

Spektrum
(800) 338-4639
www.spektrumrc.com

Written by Chris Mulcahy
A fully capable sport scale fun flier
Abridged product review
Photos by the author
Read the full product review in the July 2016 issue of Model Aviation.

Specifications

Model type: Sport scale ARF
Skill level: Intermediate
Wingspan: 65 inches
Wing area: 747 square inches
Length: 55 inches
Weight: 5 pounds without battery
Power system: Torque 4016T/500 MKII brushless motor; Airboss 80-amp ESC; 6S 3,000 to 4,000 mAh LiPo battery
Radio: Minimum five-channel transmitter and receiver; six servos
Street price: $349.95

Test-model details

• Radio system: Futaba 14SG transmitter; Futaba R617FS receiver; six Hitec HS-7245MH servos; 6-, 12-, and 24-inch servo extensions; Extreme Flight aluminum 1.25-inch servo horns
• Power system used: Torque 4016T/500 MKII brushless motor; Airboss 80-amp ESC; 6S 3,000, 3,300, and 5,000 mAh LiPo battery packs
• Flying weight: 5.5 pounds without battery
• Flight duration: 5 to 10 minutes, depending on battery size

Pluses

• Stable, easy-to-fly aircraft.
• High-quality build and hardware.
• Lightweight.
• Wide range of power options.
• Floats available.
• Hard points for floats already installed.

MINUS
• Wheels were extremely noisy; needed grease.

Abridged product review

The Legacy Aviation side of Extreme Flight is the home of its general aviation sport airplanes. One of the company’s latest offerings is a 65-inch Turbo Duster, based on the real-life workhorse, the Air Tractor. The full-scale Air Tractor is used for a variety of crop-dusting and firefighting duties, and is built in Texas.

The Turbo Duster that I am reviewing is a generic version of the Air Tractor that can be easily tailored to be a nice-looking scale model of any of the variants. As of this writing, a float set is in the process of being released. It will open a new aspect of flying the Turbo Duster, and will be perfect for modeling any of the firefighting versions out there.

The power for the Turbo Duster comes from Extreme Flight’s recommended power system—in this case, a Torque 4016-500 motor coupled with an Airboss 80-amp ESC. The recommended propeller is a 16 x 7, and a Xoar 16 x 7 electric propeller was provided. I used the suggested Hitec HS-7245MH servos (six are required) with Extreme Flight 1.25-inch aluminum servo arms. Extreme Flight also carries spinners and servo extensions.

All of the accessories used in the review are available from Extreme Flight.

The recommended Torque motor and Airboss ESC are installed.

I used my Futaba 14SG transmitter with a Futaba R617FS receiver. The Turbo Duster features full-range flaps, which means that the flaps can travel all the way up, as well as down. This opens up a wide range of mixing possibilities. (You will need at least a seven-channel radio and receiver to have all of the control surfaces on their own channels.)

I chose to set up three modes for my aircraft. The first was a conventional flap setting with the flaps assigned to a slider switch on my 14SG so that I could position the flaps in any lower position.

The second setup was a mix that combined the flaps with the ailerons, essentially creating a full-span aileron on the wing. The third mix can be called crow, butterfly, and/or air brake. This mode deflects the flaps and ailerons opposite of each other to slow the airplane.

Flying

The flaps are fun to play with! With full flaps, the airplane will float along at a walking pace, and short field landings are a piece of cake. With a good headwind, I was able to land with what seemed to be roughly a 1-foot rollout. The ailerons have good authority by themselves, but when combined with the flaps, they give a stronger effect. It’s similar to switching to high-rate ailerons. It gives a crisp feeling when starting and stopping a rolling maneuver.

The ailerons and flaps are controlled with HS-7245MH servos. Aluminum 1.25-inch servo horns were also used.

The butterfly/crow/air brake feature worked great as well. In a complete nosedive, the air brake acts as a parachute and slows the airplane’s descent. I was able to start up high and nosedive vertically into a landing.

On a conventional landing, if either the approach is too fast or you want to stop short as you are touching down, the air brake does a great job of slowing the airplane. I assigned the air brake function to a momentary switch so I wouldn’t inadvertently leave the air brake mix activated. This worked well for “tapping the brakes” on runway approaches.

Here you can see the deflection that’s possible with the flaps and ailerons.

The Duster is a perfect sport flier. It flies as easy as any trainer. If you want to take it to the extreme, the Turbo Duster can handle 3-D maneuvers. With its low-dihedral wing, however, it would not be my first choice for a 3-D-only flier. This airplane bridges the gap by giving you an awesome sport flier with scalelike looks, but if you want to rip up the sky with it, you absolutely can.

Extreme Flight makes it easy to get the recommended gear you need to complete the model because its website is a one-stop shop.

The Turbo Duster is big enough to present well in the sky, yet small enough to pack into most vehicles for transport. The airplane’s overall quality is outstanding—everything fit and was finished the way you would expect. I didn’t find any problems with the construction.

I look forward to adding the floats. I think this model will make an excellent floatplane, and hard points for the floats are already built in. In the meantime, I’ll keep “dusting” cornfields and practicing ridiculously short takeoffs and landings!

—Chris Mulcahy
cspaced@gmail.com

Bonus video

Manufacturer/Distributor

Extreme Flight
(770) 887-1794
www.extremeflightrc.com

Sources

Futaba
(800) 637-7660
www.futabarc.com

Hitec
(858) 748-6948
www.hitecrcd.com

Written by Barry Vaught
Lakeland is the place to be in March for jet pilots
Event coverage
Photos by the author
As seen in the August 2016 issue of Model Aviation.

Bonus Photos

Event coverage

Florida Jets week, held March 7-12, 2016, started Florida’s RC air show season with two great events, 165 pilots, more than 200 jets, highly skilled talent, thrilling entertainment, and lots of fun in the sun. The Red Flag event, which was covered in the July 2016 issue of Model Aviation, took place the first three days, followed by Florida Jets.

Some of the pilots who participated in the Red Flag RC Jet Aerobatic Competition were ready to simply fly their jets in a fun, noncompetitive manner and burn a lot of fuel. Florida Jets has a large following and is a “jet-together,” where electric and turbine pilots can safely fly their jets almost as many times as they want.

Mark Petrak’s Tomahawk Design Alabtros L-39 XXXL is 1:2.7 scale. Its 12-foot wingspan can carry more than 100 pounds of weight. The model, built by Joseph Kager, received the Critics’ Choice Award.

Greg Foushi and Bill Freeland display their F-16s. Greg and Bill are members of the Remote Control Association of Central Florida in Apopka FL.

Barry Hou, Greg Foushi, and Kristopher Gunter, standing in the front of their tent, are enjoying this year’s Florida Jets!

Surprises come early when Ali Machinchy is attending an airplane event. Ali is a magician with airplanes and it is always fun to see what he is flying at the events because he prefers to fly a variety of airplanes. He brought a one-of-a-kind Turbo Spitfire, an Avanti Viper XXL, and an F-86 Tomahawk Sabre.

Ali Machinchy’s impressive, custom Turbo Spitfire has a 91-inch wingspan, 32-pound flying weight, and is powered by a turboprop.

Ali Machinchy’s F-86 Tomahawk Sabre is an all-composite, 1/3-scale, 128-inch wingspan jet that weighs 45 pounds. It received the Best Scale Jet Performance award.

The Turbo Spitfire is an ongoing custom project that flew and sounded great. It needed a little help while taxiing because of the crosswinds. Ali’s 1/3-scale Avanti Viper XXL is a beautiful jet and flies smoothly. We mounted a GoPro HERO4 camera on the elevator stabilizer to chronicle the flight. I was concerned about mounting a camera on his aircraft, but the flat adhesive GoPro mount was easily removed by simply twisting the camera. Ali’s 1/3-scale Tomahawk Sabre is beautiful and flew as nicely as the Viper.

Barry Hou brought an unusual English Electric Lightning that has the turbines mounted vertically, one above the other. Full-scale pilots have described flying the aircraft as “being saddled to a skyrocket.”

A less expensive way to start flying turbine jets is to build your own. Dana Thrasher’s Turbinator was built from a kit. He purchased a used turbine and has approximately $4,500 invested in the jet. The Turbinator flew well and looked great in its Marine Corps color scheme.

Barry Hou’s rare English Electric Lightning relies on two KingTech 160 turbines. One jet turbine is situated above the other.

Dana Thrasher’s Turbinator has a 76-inch wingspan. The 26-pound model is powered by a P-140X turbine.

Jeff Stubbs’s BAE Hawk on final approach in a stiff crosswind.

It is always heartwarming to see a father and son enjoying our great hobby together. Joey Tamez and his son, Joshua, traveled from Texas with their yellow Navy Shockwave.

Kristopher Gunter brought an F-15 Eagle, which has a special “Let’s Roll” symbol on the fuselage in the spirit of 9/11. This symbol is displayed on various full-scale aircraft throughout the Air Force as a way of recognizing the heroes and victims of the September 11 terrorist attacks on the United States.

The halftime shows included some of the best ever at Florida Jets, with demonstration flights from some of the Red Flag RC Jet Aerobatics pilots and formation teams.

Father and son, Joey and Joshua Tamaz, display their Shockwave. The 80-inch wingspan model received the Best Sport Jet award.

Kristopher Gunter and his F-15 Eagle with “Let’s Roll” painted on the fuselage.

The flightline was filled with spectators on the west side of the field at the start of the halftime show.

The Florida Jets runway walk allowed the spectators to see the aircraft up close and meet the pilots.

Many people are involved in RC airplane events to make them safe, entertaining, and successful. Sam Wright has been announcing Frank Tiano’s RC events for 29 years.

John Walsh is a former air traffic controller and serves as the onsite air boss. He monitors full-scale air traffic while the RC event is in progress. If there is a full-scale aircraft emergency, the RC models will be grounded until the emergency is over. The Lakeland Linder Regional Airport is extremely cooperative and this is a good example of how full-scale aircraft and RC aircraft can work together for the benefit of everyone.

Congratulations to Frank Tiano and everyone involved for another exciting, memorable Florida Jets.
—Barry Vaught
bvaught@cfl.rr.com

Florida Jets Special Awards

Sources:

Florida Jets
Frank Tiano Enterprises
www.franktiano.com

Jet Pilots’ Organization
www.jetpilots.org

Written by Lawrence Klingberg
Creating Golden Age Classics from a Cub kit
Construction article
Photos by the author
As seen in the August 2016 issue of Model Aviation.

Bonus photos

Convert an aircraft to a model using a Cub kit

• Curtiss Robin
• Waco Cabin aircraft
• Bellanca Skyrocket
• Fairchild FC-2
• Stinson Detroiter
• Monocoupe
• Travel Air 6000

Throughout the last 10 years, I have found that modifying or changing a basic Balsa USA 1/3-scale Cub kit into a high-wing classic from the 1920s to 1930s is a project that is enjoyable and might be of interest to modelers with slightly better-than-average skills. This modification is not difficult, but does require many changes to create a great scale model.

Aircraft that I’ve modeled include a Monocoupe, Waco Model E, a Fairchild FC-2, and many others. In looking through the Juptner U.S. Civil Aircraft Series books or others, there are so many high-wing airplanes that are not that difficult to replicate.

The Monocoupe was designed by Don Luscombe in 1926. Throughout the years, 5,000 of the clipped-wing aircraft were sold.

If this article inspires you to build a different type of aircraft, be sure it is within your capabilities.

Fuselage

The fuselage is the most difficult part of the airplane to modify. To begin, put the Cub fuselage plans on the bench and cover it with tracing paper. These will be your plans for the side and top view of the proposed model.

Draw a centerline on the paper to reference measurements for translating them from the three-views to your plans. A good starting point is to draw in the wing and stabilizer on the plans in their respective locations. They should not be changed, because it would alter the center of gravity and flight performance would be affected.

This is a side view of the Balsa USA Cub’s fuselage. Drawing courtesy of William Hannan.

For this article, the Bellanca Skyrocket will be used as the example of how to modify the Cub’s fuselage and other parts. Although the Skyrocket’s side view is a drawing of a Peanut Scale airplane by Bill Hannan, it still coveys the outline that can be used for our purposes.

Let’s start to draw up the side-view plans. Start by drawing the top and bottom outlines and then draw in the upright and bracing diagonal pieces of wood. When this drafting work is completed, it’s time to cover the plans with something to protect them from glue. I use the backing from Solartex covering to protect the plans. It works better than wax paper and glue does not stick to it.

While on the subject of making the fuselage sides, always make one on top of the other, ensuring two identical sides. I use gussets at every joint on the fuselage. If I make up approximately 200 pieces before starting construction, there will be enough to finish the job.

When the two fuselage sides are finished, remove them and stand them up over the top view of the Cub plans and use a T square to hold up the sides. Pin them down before starting to cut the pieces of wood to create a square fuselage. Be sure to gusset each joint and check that the fuselage is straight and true at all stations.

At this time, I also install crossbracing to the top and bottom of the fuselage for added strength. By now the framework should start to look like an airplane. It is often best to leave the front portion of the airplane until last to finish. This allows ample time to consider engine mounting, windshield location, what kind of cowl will be used, and whether or not a dummy radial engine, such as many old aircraft used, needs to be made.

Wings and Wing Center Section

I like to build a wing center section at this point, which is made up as a unit to be attached to the fuselage with metal pieces screwed on and also wood pieces put on with epoxy glue.

Note that the leading edge (LE) is made from thin aluminum sheet. There is also a 11/2-inch hole in the center section ribs for the aileron wires to go through to connect the servos in the wing.

I made a few other changes concerning the Balsa USA Cub wing. The first thing I changed was to build the wing halves with aluminum LEs (see “Tin Wings” in the July 2010 issue of Model Aviation).

Another change, as pointed out in the article, would be to use a hole cutter to make holes in the wing ribs before putting the wing halves together. The 11/8-inch holes are the size of the cardboard tubes that the Solartex is wrapped around.

The last modification to the wing is to build the ends of the wing so that it has the somewhat square tips, as shown in the Skyrocket wing three-view.

The ends of the wing have somewhat squared-off tips as shown in this sketch.

The Stabilizer and Rudder

The easiest job of all during this modification is the construction of the tail feathers. The stabilizer and rudder outlines are drawn so that all of the necessary ribs and hard points are in the right places. Design the ribs so that they are full-flying surfaces.

If the plans are finished, go ahead and build the stabilizer and rudder. Sometimes it is a good idea to use two long 6:32 screws and run them up through the fuselage and stabilizer and then into the rudder bottom, which has T-nuts for the screws to enter. I have found this method of attaching the stabilizer to the rudder to be solid.

To further strengthen the tail members, I make K&S Precision Metals streamlined tubing struts to run from the top of the rudder down to the stabilizer and then to the bottom of the fuselage. Aluminum end pieces are epoxied into the tubing and then fastened with 4:40 screws to hold everything together.

The rudder can use a pull-pull system for control with the servo mounted roughly 18 inches from the wing’s LE on the bottom of the fuselage. Likewise, the stabilizer can be controlled in a similar manner.

This is the typical shape of the stabilizer and rudder ribs. A Du-Bro hinge is shown.

Wing Struts

Now is a good time to make the wing struts to hold the wings. I install two pieces of aluminum stock through the fuselage sides in two places (locate as required). The 5/8 x 1/8-inch aluminum pieces are 11/4 inches long. This allows approximately 5/8 inch to extend past the fuselage on both sides, so the struts can be bolted to the wing with 11/2-inch 4:40 screws. These strut anchors can be screwed and epoxied to the airframe.

To arrive at the true strut length, the fuselage must be weighted down in the middle of an 8-foot long workbench. The wing is attached with four screws at the center section, and boxes are placed under both sides for support.

We want the wings to have roughly an inch of dihedral at each end. This amount will be approximately 151/2 inches under the end of each wing half.

The Skyrocket’s wing struts are slightly different from most struts, such as those the Cub uses. These struts are the lifting airfoil type.

The all-balsa LE is shown. The end view of the strut shows the 1/8-inch pine “backbone” of the strut.

To make this type of strut, pieces of 1/8-inch balsa for the ribs must be cut and glued every 3 inches onto a 21/2-inch piece of 1/8-inch pine that is approximately 34 inches long.

After making four struts, they are carefully measured and the end metal pieces are attached with screws to the 1/8-inch pine strut end. The other end of the strut is K&S Precision Metals 3/4-inch aluminum. Airfoil the tubing at the ends with metal pieces epoxied into them. These attach to the wing after being measured for length.

The Engine Room

As stated in the beginning of the article, the forward section of the aircraft is the most difficult to build. By this time, most builders have given thought to how to construct this portion of the airplane from the side view.

My approach to this has been to draw the front end of the airplane on the plans and make a 1/8-inch door skin “phantom” nose section to get the front dummy radial engine ring location and the real engine firewall located, both on the plans and on the airplane.

The side view is cut from door skin and temporarily glued at the centerline location of the airplane, taking on the tapered shape of the dummy engine mounting ring.

Don’t be fussy about these pieces because they will be cut out later to make room for the actual front ring and engine firewall. These two pieces, when glued in place, form a cross, which is the center for locating and mounting the engine on the firewall. Everything must be kept concentric.

This shows the front sketch of the Skyrocket.

Now that the dummy engine ring has been placed, you must decide to fully cowl the radial engine or to have the cylinders exposed. I prefer to assemble the radial engine with products purchased from Williams Brothers Model Products.

The 1/4-scale cylinders make a realistic-looking engine, provided you make a wooden crankcase and mount it on the engine ring. They can be cowled or you can fabricate a speed ring from them. Either way, they look great and add much realism to the aircraft’s nose.

For a fully cowled version of the Skyrocket, an aluminum cowl from Balsa USA, designed for a 1/2-scale Sopwith Pup, is perfect. Its inside dimensions are 131/2 inches and the dummy radial is slightly smaller. The speed ring is another option, but it must be made by the builder.

Finally, the area from the end of the cowl to the start of the cabin must be considered. There are two choices.

One solution is to make aluminum panels to cover the area. I make cardboard templates of everything and then cut parts from thin aluminum sheeting, leaving 3/8-inch overlap on all seams. They are attached to the framework with #1 Phillips-head screws, spaced roughly an inch apart. These screws are available from Micro Fasteners and hold the panels on nicely.

Another way to cover the area is to make removable panels backed by formers and cover them with 1/32-inch sheet plywood. These can be glued on or made removable for engine access.

The engine and fuel tank mounting methods are up to the builder. The instrument panel and windshield can be left until last, again fabricating cardboard templates for patterns.

This shows the front of the airplane before installing the aluminum covering.
Note the instrument panel in the cockpit.

Finishing the Airplane

After all of the model’s modifications are finished, I like to assemble everything and make sure that all of the components work and all of the parts fit before final sanding and applying four coats of Balsarite to the airframe. If everything is okay, it is then time to cover with Solartex.

After I’ve completed the covering, I put pinked tape on all of the seams and do all of the wing ribs, giving the airplane a finished appearance. For painting purposes, my choice is Rust-Oleum. It comes in easy-to-use spray cans, and once applied, it lasts indefinitely.

If graphics are needed, they can be painted or purchased from a stationery or craft store (letters, numbers, etc.).

Landing Gear

I’ll not spend much time describing the landing gear. Most builders make them from 1/4-inch steel rods and either silver solder or braze the joints together as needed. They are usually covered with balsa shaped to an airfoil, covered with Solartex, and then painted.

Pontoons or Floats

It has been my experience in the last 25 years that the most fun is equipping an airplane with pontoons. I have constructed roughly 10 pairs of Balsa USA 1/3-scale floats and used them on all sorts of large aircraft, so I feel that they are a worthy addition to the Skyrocket.

You need to build some hard points into the bottom of the fuselage to accommodate the struts that go between the pontoons and the lower portion of the fuselage. If float flying is a possibility, plan for it now.

This is a side view of the Skyrocket on floats.

Keep ’em Flying and Build ’em Big

I hope this article inspires a host of builders to try out the ideas set forth and see what they can come up with.

The author assumes no responsibility for results or performance of any modified kit and has submitted the information purely for the enjoyment of creating a scale airplane from a Cub kit.
—Lawrence Klingberg

Sources:

Balsa USA
(800) 225-7287
www.balsausa.com

Solartex
www.shop.balsausa.com/category_s/119.htm

K&S Precision Metals
(773) 586-8503
www.ksmetals.com

Balsarite
www.coverite.com/accys/covr2500.html

Williams Brothers Model Products
(512) 846-1243
www.williamsbrothersmodelproducts.com

Micro Fasteners
(800) 892-6917
www.microfasteners.com

Rust-Oleum
(877) 385-8155
www.rustoleum.com

Written by Jon Barnes
Fly with the Marine Corps
Abridged product review
Photos by the author
Read the full product review in the August 2016 issue of Model Aviation.

Specifications

Model type: Foam electric warbird
Skill level: Intermediate
Wingspan: 48 inches
Wing area: 431 square inches
Length: 38.2 inches
Weight: 53 ounces
Power system: Brushless electric system (included)
Radio: Spektrum DX9 DSMX nine-channel transmitter
Construction: Z-Foam
Street price: $269.99

Bonus video:

Test-Model Details

Motor used: E-flite 850 Kv 15 brushless electric outrunner (installed)
Speed controller: E-flite 40-amp brushless with BEC (installed)
Servos: Six Spektrum A330 nine-gram submicro servos (installed)
Battery: Three-cell 11.1-volt 25C 2,200 mAh LiPo
Propeller: Four-blade 10.5 x 8
Radio system: Spektrum AS3X-equipped AR636A six-channel receiver (installed)
Ready-to-fly weight: 53 ounces
Flight duration: 4 to 6 minutes

Pluses

• Rough-and-ready blue and green U.S. Marines paint scheme.
• Scalelike operational rotating main electric retracts.
• Removable external fuel tanks.
• AS3X stabilization offers superb slow-speed stability and handling.
• Multipaneled flaps closely emulate those used on the full-scale airplane.

Minus

• No scale underwing armaments included.

Manufacturer/distributor:

Horizon Hobby
(800) 338-4639
www.e-fliterc.com

Sources:

Spektrum
(800) 338-4639
www.spektrumrc.com

Written by Andrew Griffith
An easy soaring experience
Abridged product review
Photos by the author
Read the full product review in the August 2016 issue of Model Aviation.

Bonus video

Specifications:

Model type: Powered glider
Skill level: Beginner
Wingspan: 59 inches
Wing area: 405 square inches
Wing loading: 7.1 ounces per square foot
Airfoil: Flat bottom
Length: 39.6 inches
Weight: 20 ounces
Power system: 370-size brushless electric
Radio: Four-channel minimum DSM2 or DSMX
Construction: Z-Foam
Covering/finish: Painted foam
Street price: $169.99

Test-Model Details:

Motor/engine used: E-flite 370 brushless motor (included)
Battery or fuel: E-flite 2S (7.4 volts) 1,300 mAh LiPo (included)
Propeller: Two-blade folding propeller (included)
Radio system: Spektrum DX18G2
Ready-to-fly weight: 20 ounces
Flight duration: 5 to 10 minutes

Pluses:

• What little assembly is needed can be completed in 30 minutes.
• Easy to fly for beginners, but fun for more experienced pilots.
• AS3X lets the Conscendo handle wind that would ground most foam airplanes.
• Easy access to change battery.

Minus:

• There were a few places where the glue was oozing out of joints.

Abridged product review

Learning how to fly RC without an experienced instructor has been universally discouraged. For me, one of the most gratifying aspects of the hobby is the friends I’ve made at the clubs I have belonged to and the events I have attended.

Those things noted, not everyone has easy access to an instructor, so Horizon Hobby produced the HobbyZone line so that those who don’t have the luxury of having an instructor can still find success within our awesome hobby.

SAFE technology is a technological leap forward toward this goal. SAFE stands for Sensor Assisted Flight Envelope and allows the pilot to choose an appropriate flight mode for his or her experience level, as well as having a panic recovery mode available at the flip of a switch in case things go awry.

With its SAFE receiver in beginner mode, a model will only bank enough to turn or pitch up or down enough to climb or descend, but no matter how far you move the stick or how long you hold it, the airplane won’t get in trouble.

In beginner mode, the airplane self-levels if the sticks are released to center. Intermediate mode gives you more control and maneuverability, but the model still won’t loop or roll inverted. Self-leveling is available by switching back to beginner mode or pressing the panic button.

When you’re ready for the big time, advanced mode unlocks the full potential of the Conscendo. While flying in advanced mode, the model won’t self-level unless you hit the panic button, but the stabilization system is still active, making flying in gusty wind not only possible, but enjoyable.

The Conscendo is a Z-Foam motor glider with a 1.5-meter wingspan and a 2S 370-size brushless power system. Some sailplane purists still snub their noses at motor-powered gliders, but love them or hate them, they are a convenient, self-contained method of launching a glider. This convenience leads to more flying, which ultimately leads to more enjoyment of the hobby which, after all, is what it’s all about!

Like many motor gliders, the Conscendo features a folding propeller to minimize drag when the motor is shut off. Control is provided via ailerons, rudder, elevator, and throttle.

Construction

The Conscendo S comes in two versions: an RTF version that includes a DX4 four-channel transmitter, and a BNF version that requires a four-channel DSM2/DSMX full-range transmitter. I received the BNF version for review and I’ll be using my DX18G2 because it never hurts to have 14 channels in reserve, just in case.

A 2S LiPo battery, DC car-style charger, and an AC adapter are all included. It’s actually kind of clever; the power supply has a receptacle that the car charger plugs into, then the whole thing plugs into the wall. It’s pretty simple—plug it in, connect the battery, and the light flashes while it’s charging and comes on steady when the charge is complete. I plugged in the battery and started charging it while I read the remainder of the manual.

The included charger can be used nearly anywhere. The battery plugs in via the balance port and the car charger can be powered either by a car outlet or the included AC power supply.

Although the RTF version already has the radio bound and set up, the BNF version requires some programming specific to the SAFE receiver. A chart outlines the programming sequence for your particular radio and it only took a few minutes to set up the mode switch, panic recovery (buddy-box pushbutton), and dual rates needed for the Conscendo.

Binding the receiver is easy because a short servo extension is attached to the bind port that surfaces in the battery hatch. Plug a bind plug into the extension and bind the radio.

Four screws and two aileron connectors can be removed to transport the Conscendo without the wings attached, but at 1.5 meters, it can fit in most vehicles without disassembly and I leave mine put together.

A servo extension is provided so you can easily put the AS3X receiver into bind mode. A battery tray and strap, as well as hook-and-loop material, are provided to secure the battery.

Flying

I gave the Conscendo a gentle, level toss and advanced the power. The model climbed well at roughly a 30° angle and quickly reached altitude. I cut the power at approximately 200 feet and let the Conscendo S glide. The model slowed nicely, and while not being a “floater” per se, it flies slowly enough for beginners. In advanced mode, the Conscendo really comes alive for experienced pilots. With the power on, the aircraft will perform loops, rolls, stall turns, and even some spins.

The word Conscendo is Latin for “to rise up” and the Conscendo certainly lives up to its name. Even in the lightest lift, the aircraft would indicate lift was present with a bump. After it was centered in even the most modest lift, it would circle tightly and climb well. Very impressive!

With half power, a gentle toss slightly above the horizon is all that is required to launch the Conscendo. It will fly right out of your hand, and the AS3X system will keep it from doing anything scary during launch and climbout.

I felt that flying inverted was a good time to test panic-recovery mode. When I pressed and held panic mode (the trainer switch on my DX18), the Conscendo immediately rolled upright and assumed a gentle climb.

This feature is great for the occasional loss of orientation that beginners often fall victim to or for those pilots making the switch to advanced mode. Confidence can be inspired while still having a safe outlet if you get confused. Let me offer a word of caution on panic mode, though; you need sufficient altitude for panic mode to recover the airplane, so don’t wait until the last second to press it.

Because the Conscendo is not equipped with spoilers or flaps, and it will float a long way with power off unless there’s some wind, you need to make sure that you have enough room to land the aircraft. It took several flights, but with some practice, I could regularly sideslip the little airplane into our 15-foot spot-landing circle. There are plastic skids on the bottom to protect the foam so you can land it on paved surfaces if you need to, but grass landings are preferred.

Under power, the Conscendo S is spirited and aerobatic enough to be fun, even for skilled pilots. The provided black stripe decals make a big difference in aiding visibility as the model climbs in thermals.

Conclusion

The HobbyZone Conscendo fills a lot of roles, and I’m glad I have one. A beginner will appreciate the Conscendo’s SAFE technology, panic recovery, and the slow flight characteristics. Intermediate pilots will appreciate having an airplane that grows with them.

Glider pilots will like the Conscendo because it’s small enough to keep handy, it can be hand-launched, and it thermals well enough to be fun. Advanced pilots will love the lively performance the Conscendo is capable of in advanced mode. This airplane truly does offer something for everyone.

—Andrew Griffith
andy@customcutgraphix.com

Manufacturer/Distributor:

Horizon Hobby
(800) 338-4639
www.hobbyzonerc.com

Sources:

Spektrum
(800) 338-4639
www.spektrumrc.com

Written by Terry Dunn
A refined aerial media platform
Product review
Photos by the author
As seen in the August 2016 issue of Model Aviation.

Bonus video:

Specifications

Type: Prebuilt quadcopter
Skill level: Beginner and beyond
Frame diameter: 350mm
Radio: 2.4 GHz system (included)
Minimum flying area: Large park
Needed to complete: Smartphone or mini tablet
Power system: Four outrunner brushless motors with 9.4 x 5 propellers; 4S 5,350 mAh LiPo battery (all included)
Duration: 21-plus minutes
Flying weight: 49.1 ounces
Price: $1,399

Pluses

• Excellent 4K-resolution camera.
• Wide performance range.
• Carrying case included.

Minus

• Video downlink is spotty.

Product Review

In 2013, I had the opportunity to review the original version of the DJI Phantom. It made waves as one of the first RTF multirotors capable of carrying a camera. It would be easy to make a case that the Phantom was responsible for kick-starting the current multirotor craze.

The past three years have witnessed the Phantom undergo rapid and constant evolution. All of those updates are reflected in DJI’s newest model, the Phantom 4.

At a glance, the newest Phantom does not appear to be that different from the original model of the series, but looks can be deceiving. The quadcopter’s plastic exoskeleton hides a long list of improvements that make it a more refined and capable flying machine.

About the Phantom 4

The Phantom 4 is only available in a complete RTF package. You get the quadcopter, a transmitter, one battery, a charger, and two full sets of propellers. Although nothing else is technically required to fly the Phantom 4, you need to use a smartphone or tablet to perform initial setup and calibration tasks. You will probably want to incorporate this device during every flight in order to take advantage of the telemetry and video downlink that it affords.

The prebuilt DJI Phantom 4 multirotor includes all of the components needed to fly.

The transmitter has a clamp to hold your smart device. It will hold a smartphone or a smaller tablet. I alternated between an iPhone 5S and an iPad Mini during my testing. Getting video and telemetry from the quadcopter requires you to physically connect the device to the transmitter via its built-in USB port. Using a 10-inch cable allowed me to connect the device without having to manage a tangle of extra wire.

The included transmitter has a simple control layout and features a built-in mount for smartphones and small tablets.

I like the transmitter’s simple and clean appearance. The front face has only the control gimbals, a power button, and a button to engage the “return to home” function. The top edge of the transmitter contains a few dials and buttons for various purposes. These controls are easy to reach while flying. There are two programmable buttons on the back side of the case.

The quad’s frame measures 350mm diagonally, with an outrunner brushless motor mounted on each corner. Stout, spring-loaded clips on each motor allow the propellers to be quickly and easily installed without tools.

My only concern with this mounting method is that the propellers do not have through holes, threads, or any other way to mate them with a propeller balancer. With that stated, I must confess that the propellers I’ve used on the Phantom 4 have demonstrated no signs of being unbalanced.

A cornerstone feature of the Phantom 4 is its three-axis gimbal with an integrated camera. The gimbal keeps the camera locked on its subject as the quadcopter gyrates through the sky. Despite the camera’s small size, it boasts impressive specifications. It can shoot 4K video at 30 frames per second (FPS) and 12-megapixel still photos. The camera has a wide-angle lens, but no horizon-bending fish-eye effect.

The propellers clip into place on the motors without the use of tools. It is a simple, yet effective, system.

The Phantom 4’s integrated camera and gimbal assembly is capable of capturing high-quality 4K resolution video and photos.

A four-cell 5,350 mAh LiPo battery powers the Phantom 4. The plastic housing around the battery slides into the quadcopter’s frame and clips into place. The electrical contacts automatically engage when the battery is fully installed.

The provided simple AC charger simultaneously charges the flight battery and the transmitter. It takes approximately an hour to charge a fully depleted flight battery. The transmitter needs three to four hours to charge, but a single charge should last for several flights.

The LiPo battery has a few innovative and unique features. A button on the battery case is used to turn the battery on or off, which effectively controls whether power is sent to the electrical contacts. A series of LEDs indicates the charge status, the battery’s overall health, and any errors or malfunctions. If the battery sits unused for 10 days, it will automatically discharge itself to a safe storage voltage.

A 4S 5,350 mAh LiPo battery provides flight times of more than 20 minutes.

All of the kit components come packaged in a handy, durable foam case. The hinge, latch, and handle use embedded plastic components. This is definitely not a cheap throwaway package.

The carrying case gathers all of the necessary parts into a surprisingly small footprint. Perhaps it’s even a little too small. Although there is a slot that nicely fits my iPad Mini, I don’t see any way to add a spare battery. The one battery that fits must be installed in the airframe.

Users who wish to bring along more than the bare essentials will need to find a larger case. Several such cases are available from DJI and aftermarket companies.

All of the components fit in a small, tough foam case.

Preparing for Flight

The piloting skills required to fly the Phantom 4 are minimal, thanks to the onboard stabilization systems, yet those same systems make it an inherently complex machine. Even if you already know which way to move the control sticks to make the Phantom go where you want, inadvertently pressing a button or flipping a switch could have drastic, unintended consequences.

For that matter, any number of circumstances could trigger an automated system to assume control of the model. It is imperative that you educate yourself on the specific systems and features of the Phantom 4 before flying it. Any previous experience you may have with airplanes, helicopters, or even other multirotors, simply doesn’t apply.

The model includes a quick-start guide that conveys the bare essentials. One of the first steps listed in the guide is to watch a series of tutorial videos. The videos are helpful and informative, but are not comprehensive. I recommend that you download the complete user manual. It doesn’t take long to read from cover to cover, but it likely will answer questions that you didn’t even think to ask.

Many of the quad’s systems and functions are managed via menus on the DJI GO app that you must install on your smart device. This includes processes for calibrating the onboard compass and selecting your preferences for the camera. It pays to familiarize yourself with these options so you aren’t scratching your head at the flying field.

The DJI GO app allows you to view real-time video feed and provides numerous menus that can be used to configure the Phantom 4.

Most camera-toting multirotors have a barometric altimeter and GPS receiver that work in unison to allow the aircraft to park in the air without control inputs. The Phantom 4 adds ultrasonic sensors on the bottom of the frame to help determine the quadcopter’s altitude.

Monocular range finders are located on the front and bottom to help the Phantom 4 be more aware of its surroundings. With these extra devices, it is possible to fly with some degree of autonomy in places where GPS signals are weak or nonexistent.

If the range finders detect an object in the flight path, the multirotor will automatically stop forward motion to prevent a collision. There are, however, a few caveats to this feature. Because the range finders are only located on the front and bottom, objects located in any other position will not be detected or avoided. I suspect that it won’t be long before multirotors are equipped with sufficient range finders (or other devices) for complete situational awareness.

There are three basic flight modes from which to choose. Positioning mode (P-mode) has the most docile control response and utilizes all of the Phantom 4’s position awareness devices. This is the flight mode that is best suited for taking photos and shooting video. It provides a smooth, stable platform for the camera.

Moving into Sport mode (S-mode) extends the quadcopter’s bank angle limits. This permits faster flying speeds (up to 45 mph) and more aggressive maneuvering. All of the positional devices are still active, but obstacle sensing is not functional in S-mode. Although it is possible to shoot photos or video in this mode, it’s best for competent fliers who are ready to explore a fast-paced side of multirotor flight.

Attitude mode (A-mode) is similar to S-mode. The difference is that you forfeit GPS and obstacle sensing. This somewhat increases a pilot’s workload, but the quad still has self-leveling and altitude-hold capabilities.

Flying the Phantom 4

Now that I’ve logged numerous flights with the Phantom 4, I have a routine that gets me in the air quickly. After I have set down the aircraft at a suitable “home” position, I power up the transmitter. I then install the battery and turn on the quadcopter.

I start the DJI GO app on my smartphone and do a quick scan of the telemetry gauges. The entire process takes less than two minutes.

I have much experience in flying multirotors, and I found flying in P-mode easy and relaxing. Newcomers to quadcopters, however, might want to tone down the controls from the stock settings via the app. You can bump them back up as your skills and confidence improve.

I recorded some video in P-mode. Because of the Phantom 4’s moderate speeds and docile response in this mode, I felt comfortable using the gimbal controls to change the camera’s tilt angle on the fly.

Three basic flight modes provide a range of flight performance suitable for many pilots.

In my experience, the live video feed to my phone was inconsistent. On most outings, it was rock solid with almost no detectable time lag. Other times, I would only get a partial image … regardless of how close the quadcopter was to the transmitter’s antenna. I have not determined what causes the intermittent downlink problems. Telemetry data appears to be solid throughout.

DJI claims that the Phantom 4 is capable of 28-minute flights. That might indeed be possible in ideal conditions. My flights have averaged slightly more than 20 minutes. This invariably includes some power-gobbling horsing around and landing with roughly 20% of the battery capacity remaining.

Moving into S-mode livens things up. The Phantom 4 is capable of surprising speed and maneuverability. You should not expect it to perform similar to a racing quadcopter, but it’s no slouch. If you think of a racing multirotor as a Corvette, then the Phantom 4 is similar to a four-door sedan with a V-8 engine.

A-mode feels much like S-mode. Because I use both modes for the occasional high-speed run or a little goofing off, I don’t miss having GPS.

All of the video that I’ve captured so far has been at 4K/30 FPS. The raw footage is stunning—the image is sharp and the colors look natural. I am excited to try recording in other camera settings, particularly 1080 pixels at 120 FPS. That should be great for fast action shots.

When flying in P-mode, you can access special features such as Tap Fly and Active Track. With Tap Fly, when you touch an object on the video downlink screen, the Phantom 4 will automatically hover above it.

Active track is similar, but the subject can be moving. The quadcopter will attempt to stay with whatever (or whomever) you select while keeping the subject in the camera’s view. Although these features work well, I don’t think that either one is an option that seasoned fliers will often turn to.

Conclusion

I didn’t need much time with the Phantom 4 to realize that it’s vastly different from the original Phantom released a few years ago.

We still have far to go before all of the pieces are in place to invent my vision of the perfect aerial photography multirotor, but the Phantom 4 is a step in the right direction. It has a superb camera and flight modes that are applicable to a range of flying skills.

Pilots who take the time to learn and understand its myriad capabilities will discover that they are at the helm of a very potent aircraft.
—Terry Dunn
terrydunn74@gmail.com

Manufacturer/Distributor:

DJI
(818) 235 0789
www.dji.com

Written by Andrew Griffith
A Pitts biplane evolved
Abridged product review
Photos by the author
Read the full product review in the September 2016 issue of Model Aviation.

Bonus video

Specifications

Model type: Semiscale aerobat
Skill level: Intermediate to advanced
Wingspan: 48 inches
Wing area: 840 square inches
Wing loading: 17.8 ounces
Wing cube loading: 7.4
Airfoil: Symmetrical
Length: 49.3 inches
Weight: 7 pounds
Power system: 525 Kv 50-size brushless outrunner motor
Radio: Full-range six-channel DSM2/DSMX radio system
Construction: Z-Foam
Covering/finish: Paint and decals over Z-Foam
Street price: $ 399.99

Test-model details

Motor used: E-flite 50-size brushless motor (included)
Battery: E-flite 6S (22.2-volt) 4,400 mAh LiPo
Propeller: 15 x 5.5 two-blade (included)
Radio system: Spektrum DX-18G2
Ready-to-fly weight: 6 pounds, 8 ounces
Flight duration: Five minutes

Pluses

• Fantastic-looking, detailed color scheme.
• Unique pin system makes wing installation easy.
• Very aerobatic and fun to fly.
• Top hatches for convenient battery and radio system access.

Minus

• Main landing gear fairing didn’t align with fuselage on my model.

Abridged product review

One thing is certain—whether it’s cutting ribbons, racing cars down the runway, or putting on one of his “high octane” aerobatic shows—Skip Stewart knows how to entertain air show crowds with his P-2 Prometheus biplane.

Horizon Hobby teamed up with Skip to make a series of models of his modified series of biplanes. The P3 Revolution is available as both an ultra-micro (UMX) and a 60cc built-up version, and right in the middle is the P2 Prometheus.

The P2 Prometheus comes in two versions, Plug and Play (PNP) or BNF. The difference is that the BNF version includes a factory-installed AR636 AS3X receiver. The BNF version is the subject of this review.

Assembly

I unpacked the model to inspect the parts and sat down with the instruction manual. Despite damage to the outer box by the shipping company—serious enough that I made the delivery driver wait—the packaging is excellent and there was no damage to the aircraft.

In fact, all of the parts are bagged in plastic and secured in an interlocking foam shipping container. All of the preinstalled control horns and other sharp edges that could possibly poke holes in other parts were covered with foam blocks. Unpacking the Prometheus was like taking apart a puzzle box, and it was clear that the packaging was well thought out.

There are a couple of areas that require glue and I used Zap brand thin and medium CA. A Phillips-head screwdriver and CA adhesive are all that you need to assemble the Prometheus. A six-cell battery and a six-channel radio are required if you purchased the BNF version.

All control surfaces use ball links for a slop-free control system. The square elevator joiner, shown here, ensures perfect alignment of the elevator halves. You can also see the carbon-fiber strips embedded in the foam to prevent flexing while under load.

The removable cockpit hatch provides access to the radio compartment to bind the AR636, as well as install the lower wing bolts and aileron servo extensions.

Flying

I noticed that the Prometheus garnered even more than the average amount of attention that a new review model usually gets on a weekend. Several pilots even commented that they were thinking about getting one, but were waiting to see one in person. It seemed the wait was over.

The Prometheus broke ground after approximately 30 feet and accelerated cleanly while climbing with authority.

A few clicks of right trim and a couple of down-elevator inputs were required to get the Prometheus flying level at 3/4 throttle. The wing incidences and the motor thrustlines appear to be well tested because the Prometheus doesn’t climb or descend with power changes.

Checking the CG, I pulled the Prometheus up in a 45° upline, rolled it inverted, and let go of the elevator. The Prometheus arced gracefully toward the ground, meaning it was slightly nose-heavy. If you like a neutral CG, you either have to run a lighter battery or add a small amount of tail weight.

Moving the battery back is possible, but difficult because of the battery strap’s location. The battery would likely end up in the area between the hatches, so it would be difficult to put the strap on even if you moved it back. With all of that stated, it flew well with the CG where it was, so I didn’t mess with it any more.

A stall test was performed from both level flight and with a slightly nose-up attitude. In level flight, I reduced power and added elevator and when the stall broke, the Prometheus fell forward. When the elevator was relaxed and power was added, the Prometheus recovered and resumed flying. With the nose up several degrees and power removed, the Prometheus will drop a wing. Corrective control and power are needed to recover. Keeping this in mind, I will make sure that I don’t flare too early for landing.

The large side area and generous rudder mean that the Prometheus handles knife-edge flight extremely well.

Next, I tested the control response at the recommended rates. As I expected, with four ailerons, the Prometheus is nimble in high rate.

Mid- and low-rates made the Prometheus more docile and although it will still perform large aerobatics and knife-edge in mid-rate, it doesn’t snap or tumble as well.

A biplane has quite a bit of frontal area and that makes for a lot of drag, so it came as no surprise that pulling the power below half meant that the Prometheus would start to descend and some throttle is required to keep it on glide slope.

If you haven’t flown a biplane before, be ready for more throttle during final approach and maintain that until the main wheels are on the ground. This is a higher-performance airplane and is intended for experienced pilots. They shouldn’t have any problems landing the Prometheus.

With each subsequent flight, I had more fun than the one before it because I was getting comfortable with the airplane. Knife-edge pulls slightly to the gear but doesn’t try to roll out, and it does a pretty high-alpha knife-edge pass.

I tried some 3-D flying, and although not its forte, it does do rolling harriers and upright post-stall flying that is more stable than what I expected of the short wings. It has enough power to hover and torque roll with some reserve power for decent pull outs.

Conclusion

Many people love biplanes—they just hate putting them together and taking them apart at the field. The Prometheus flies like a big model, but will easily fit in large vehicles when fully assembled. If you have to break it down, the unique strut pins can quickly be removed and only four screws hold the wings on, so it merely takes a few minutes to assemble or break down the Prometheus.

One of the neatest features of the Prometheus is these L-shaped pins that allow for quick installation or removal of the wing struts.

Large hatches provide easy access to the radio and battery compartments, and the top-mounted battery hatch allows battery swaps with the airplane on its wheels.

The Carbon-Z construction is sturdy and the finish is excellent. Z-Foam is tough and easily repaired with standard CA glue. Although many models replicate the overall scheme of an airplane such as this, E-flite has replicated all of the detailed sponsor logos and markings and the result is a striking model.

In flight, the E-flite P2 Prometheus simply delivers!
—Andrew Griffith
andy@customcutgraphix.com

Manufacturer/Distributor

Horizon Hobby
(800) 338-4639
www.hobbyzonerc.com

Sources

Spektrum
(800) 338-4639
www.spektrumrc.com

Written by Terry Dunn
Put on your own air show with this large foam model
Abridged product review
Photos by the author
Read the full product review in the September 2016 issue of Model Aviation.

Bonus video

Abridged Product Review

If you’ve never seen a full-scale F4U Corsair perform at an air show, you owe it to yourself to punch that ticket. There are often many impressive aircraft at any given air show. But for me, nothing quite matches the sight, sound, and visceral punch that a Corsair provides.

One shining example of a surviving Corsair is part of the Flying Bulls Collection in Salzburg, Austria.The Flying Bulls’ Corsair is the inspiration for a new RC model by Staufenbiel. This electric-powered aircraft has a 55.6-inch wingspan and all-foam construction. It is a BNF model that includes a Spektrum AR636A receiver with AS3X stabilization.

The Kit

The Staufenbiel Corsair is large for a foamie. All of the airframe components are prepainted and have preapplied decals. A large, 540 Kv E-flite brushless motor is provided to propel the Corsair. It swings a four-blade propeller, which really accentuates the model’s scalelike appearance. An accurately sized pilot bust is included as well.

The Staufenbiel Red Bull F4U-4 Corsair is a large, prefinished foam model. It includes everything except a DSMX-compatible transmitter and a four-cell LiPo battery.

This model requires a four-cell 2,400 to 2,800 mAh LiPo battery. The battery fits into an angled compartment in the fuselage. An E-flite 70-amp ESC links the battery to the motor. The ESC’s built-in switching BEC provides power for the entire radio system.

A large hatch allows access to the battery compartment and some of the radio gear. The radio bay includes a Spektrum AR636A receiver and two 17-gram digital servos. These servos, like all of the others in the model, are not directly attached to the receiver. Instead, they are first connected to a circuit board that is located on a plywood mount above the wing halves.

The ailerons are actuated by another pair of 17-gram servos. A final pair of 17-gram servos is used to manipulate the model’s wing flaps. Electronic retracts are factory mounted in the wing. Like the full-scale Corsair, the wheel axle rotates 90° as the gear retracts or extends. A separate 9-gram servo in each wing panel opens and closes the landing gear bay doors.

A 540 Kv brushless outrunner motor is included and is factory mounted to the airframe.

Assembling the Corsair

Although most of the work is done at the factory, there are still several important finishing steps that need to be completed. Resist the temptation to breeze through these tasks. The Corsair is a large, powerful model that requires thoughtful preparation to ensure success. Plan to spend an evening or two to get things right.

I linked the included AR636A receiver to my Spektrum DX8 transmitter. The manual provides suggested control throws, which I followed. I also added 30% exponential to the ailerons, elevator, and rudder.

I initially used an E-flite 4S 2,800 mAh 30C LiPo battery. With this pack located in the battery slot, the model balanced approximately 1/4 inch forward of the suggested center of gravity (CG) location. I flew the maiden flight with the forward CG and quickly wished I hadn’t. I suggest that you stick with the recommended CG.

To get the CG where it should be, I moved the ESC from the motor cowling to the radio bay. I also added a hook-and-loop strap behind the battery slot. This allowed me to locate the battery farther aft. The strap also lets me use a variety of batteries while still maintaining the correct CG.

To get the correct CG, I moved the ESC to the radio bay and added a hook-and-loop strap to mount the battery outside of its molded pocket. Note the green circuit board through which all of the servo leads are routed.

The wires coming from the wing halves are consolidated into a pair of six-pin plugs. This makes installing and removing the wing halves easy.

Flying the Corsair

It might be a foamie, but the completed Corsair is a large and impressive model. It looks good sitting on the tarmac, but it looks even better in the air!

I like to hold a tad of up-elevator as I begin the takeoff roll. This prevents the nose from pointing down as the tail wheel lifts and the airplane is rolling on the main wheels. The Corsair quickly builds speed and is usually airborne before I hit full throttle.

As soon as the model is flying, I begin retracting the landing gear. It has a slow, scalelike movement. The autosequencing gear doors are also a nice touch. It takes roughly 10 seconds for all of the movement to be completed. Keep this in mind if you ever have to make a sudden emergency landing. You may be better off keeping the gear retracted than landing with it partially deployed.

The Corsair likes to be flown with a lot of power. The suggested control rates work well for large, warbird-style aerobatics. I typically use high-rate throws for the entire flight. Aileron rolls are quick and axial. When you relax the controls, the Corsair instantly ceases rolling. That behavior is a product of the AS3X stabilization built into the receiver. This model really shines when making fast, low photo passes. It looks great humming over the runway in a gentle banking turn. Although the model isn’t blazingly fast, it is reasonably speedy.

I like to land on the main wheels and let the tail wheel settle on its own. If there is a breeze of 5 mph or more down the runway, I am apt to land without flaps. I reserve the flaps for those light wind days. In either case, the Corsair is well behaved on approach and presents no real challenges for landing.

The Corsair likes to be flown fast. It excels at large, smooth maneuvers.

Conclusion

The Staufenbiel Red Bull F4U-4 Corsair has much of the same presence and appeal of the iconic full-scale warbird. Although assembly requires a few tweaks to get things right, the effort is definitely worthwhile. It is a big and powerful model that looks great on the ground and in the air.

—Terry Dunn
terrydunn74@gmail.com

Manufacturer/Distributor

Staufenbiel/Horizon Hobby
(800) 338-4639
www.modellhobby.de
www.horizonhobby.com

Sources

Spektrum
(800) 338-4639
www.spektrumrc.com

The Flying Bulls
www.flyingbulls.at/en

Written by Stan Alexander
A family affair
Event coverage
Photos by the author
As seen in the September 2016 issue of Model Aviation.

Bonus photos

Event Coverage

For 44 years now, the Mint Julep Scale Meet has signaled the start of contest season in the Midwest. Held at its longtime location at the Rough River Dam State Resort Park in Falls of Rough, Kentucky, the Mint, as many know it, once again provided a high degree of Scale competition. But more importantly, the friendships made throughout the years make it seem much more like a family affair.

For one family, Dale and Mary Arvin, their son, Jeremy, and the rest of the Arvin clan, this is an annual get-together that nobody misses. The event has long been held by the Southern Indiana R/C Modelers, but this year, the National Association of Scale Aeromodelers (NASA) took the reins, with Dale and Jeremy serving as the contest directors.

(L-R) Jeremy, Mary, and Dale Arvin have attended the last 44 Mint Julep contests!

Modelers came from across the eastern US for the May 20-22 event. With a smooth, full-scale, paved runway, models from .40-size all the way up to the 171-inch wingspan Cessna 152 were easy to handle on the asphalt. Static judging took place on Friday before the flying started on Saturday morning. A weather front rolled in on Friday, and Saturday was cool at best. We only flew one round of competition.

Al Kretz’s Stormovik placed second in Designer Scale. This was taken during the bomb drop maneuver.

David Hale’s Balsa USA 1/3-scale Nieuport 17 came in fourth in Fun Scale Novice.

The Saturday night banquet was held at a local hotel restaurant with a great assortment of food and drink. We were all having a good time with the host and emcee, Dale Arvin, who added to the evening with his “bag of fun” for everyone.
It’s a family affair with many modelers bringing their spouses and kids. Birthdays, anniversaries, and other times are all celebrated during the event. Great times for all!

With only one round flown on Saturday because of the weather, we started flying promptly at 8:30 a.m. on Sunday and put in three rounds of competition. The weather couldn’t have been better—sunny and 75° with the wind down the runway most of the day.

Competitors generally help one another. Mark Radcliff (R) listens to his caller, Evan Gaston, who finished less than a point behind Mark in Fun Scale Open.

Blake Neumann’s Ryan started life as an RC Guys ARF. Blake completely refinished the model.

Matt Hanson’s Grumman TBF Avenger was built from a Skyshark Hobbies kit.

At a contest such as this, you can bring any Scale airplane or jet and enjoy practice flying on Friday, and then fly in the competition on Saturday and Sunday. Maneuvers are simple; the takeoff, flyby, Figure Eight, landing, and realism are the only required ones. Add to this list five maneuvers of your choice, and you have your model’s flight program.

This contest is also a qualifying contest for the fall NASA Scale Classic, held just west of Pittsburgh.

The winners of this year’s Mint Julep include Jeff Pike with his Cub in Team Scale; Carl Handley with his P-47 in Fun Scale Novice; Jeremy Arvin flying his Top Flite Corsair in Fun Scale Open (most entries); Bob Patton with his Cessna 152 in Designer Scale; Mike Barbee with his T-34B in Expert; Art Shelton in Expert B class; and Mike Wartman with a much-modified Top Flite P-47 in Sportsman.

Jeff Pike’s J-3 Cub was awarded first in Team Scale.

Jeremy Arvin, along with his dad (R), prepares for another flight with his winning Top Flite Corsair in Fun Scale Open.

Mark Radcliff’s Cessna Aerobat 152 was entered in Fun Scale. Mark, the AMA District III vice president, had a great time during the weekend. His model is a Seagull ARF.

Blake Neumann (L) received the Bob Lirette Flight Achievement Award from Dale Arvin.
The winner of this award is decided by a vote of the contest flight judges.

Jim Neal’s Christen Eagle finished first in Fun Scale Aerobatics.

The high static score at this year’s event went to Al Kretz in Open Scale. His Fokker D.VII had a score of 98.88.

Next year’s event will take place in May.

—Stan Alexander
onawing4602@att.net

Sponsors

• National Association of Scale Aeromodelers
• Great Planes Model Manufacturing Company
• Rough River Dam State Resort Park
• Sig Manufacturing Company, Inc.
• Kentucky Department of Parks
• Model Airplane News
• Bob Smith Industries
• Tru-Turn Products
• Sullivan Products
• APC Propellers
• Airborne Media
• RTL Fasteners
• Frank Tiano
• Excel Hobby
• Zona Tool
• Zap Glue

Sources

Mint Julep
www.facebook.com/events/1517223745245766

NASA
www.nasascale.org

Rough River Dam State Park
http://parks.ky.gov/parks/resortparks/rough-river

Written by Rachelle Haughn
AMA member builds aircraft that save lives
Photos provided by Zipline and Ronnie Romiti
As seen in the September 2016 issue of Model Aviation.

Bonus video

“I just wanted to do something more fulfilling and things kind of fell into place.”

Some people have desk jobs, some punch a time clock each day, and others work the night shift. At some point in life, people might wonder what purpose their jobs have in the greater scheme of things. In addition to earning a paycheck, are they making the world a better place? Even more important, are they changing lives?

Longtime AMA member Ronnie Romiti, quoted above, no longer has to wonder what his answer to these questions would be. Not only is he able to apply the skills he learned through aeromodeling at work, he has a part in potentially saving the lives of people he’s never met. These men, women, and children live in remote areas of Rwanda, where delivering medical supplies to the sick and injured can be time-consuming and treacherous.

The new delivery method for such supplies might not be what you would expect. Since July of this year, life-saving blood, vaccines, and medications are being delivered by an 8-foot electric-powered airplane with whimsical painted-on eyes, affectionately named Zip.

A Zip aircraft in the final stages of its assembly. These twin-motor airplanes are designed to carry a payload of up to 3.5 pounds and travel 80 miles roundtrip without needing a battery change.

This autonomous aircraft follows a predetermined flight path that takes it to a remote medical center. When it reaches the medical facility, a box of supplies that is attached to a paper parachute is released from the airplane and lands in a designated safe zone. The aircraft then returns to the location from which it was launched.

“It’s very exciting,” Ronnie stated about working for Zipline, located off the California coast. “Every day is something new. We have a new problem to solve every day. Being in a startup [company] is extremely fast-paced.” In April, shortly after the company was announced to the public, Ronnie said he and his coworkers were concentrating on getting the Zipline to land in a smaller area that is roughly the size of a parking space.

Keller Rinaudo, cofounder of Zipline, said he decided to hire Ronnie because of his unique skillset as an aeromodeler. “Ronnie has been building planes his whole life, so he has an amazing ability to improvise and just make things work in order to move fast to get vehicles flying fast. He’s a master prototyper, and has been involved in every single new airframe we’ve built as a company,” Keller said. “Ronnie is also an insanely talented test pilot, and was able to safely fly and land early prototypes of planes when no other pilots on the planet could.”

When lifetime California resident Ronnie started working for the company in February 2015, he was the only employee with aeromodeling experience. Many of Ronnie’s coworkers at Zipline earned degrees at Harvard University, Stanford University, and Massachusetts Institute of Technology, and had worked for companies such as Google X, SpaceX, and Lockheed Martin.

“I was very intimidated at first, but they are very nice to me. As much as they’re book smart … they still have a lot to learn about RC planes,” Ronnie stated about his coworkers. “We’re learning from each other.”

Ronnie heard about the job opening through his aeromodeling club. When he applied for the position, he sent the company photos of aircraft he had built from kits and from plans. Because Zipline had not yet been publicly announced, when Ronnie went to the job interview he had to sign a nondisclosure agreement and meet company officials at a secret location. He brought along a Yellow Aircraft F-18 jet model that he had built, which seemed to make an impression.

Ronnie Romiti’s experience in building model aircraft is one of the reasons why he was hired to work for Zipline. This Yellow Aircraft Twin F-18 is one of the jets that he has built and flies.

Before accepting the position, Ronnie had run his own construction company for many years. He applied for the job at Zipline because he felt like something was missing. That “something” has been fulfilled by Zipline.

One of the first things that Ronnie had to teach his new coworkers was how to safely fly model aircraft. These lessons are the same ones that he learned more than 20 years ago when he began learning how to fly jets, Giant Scale electric-powered warbirds, and helicopters at a model aircraft club field. The safety tips that he gave his coworkers included the importance of establishing a flightline, to always fly with a spotter, and that they should never fly above people.

Ronnie immediately dove into helping design a twin-motor aircraft that could carry a payload of up to 3.5 pounds, fly 80 miles roundtrip without changing the battery, and safely drop a box from 40 feet above ground.

The aircraft he helped fine-tune weighs 22 pounds, can fly up to 60 mph, is safe to catch by hand, and is launched from a compressed-air catapult mechanism. “I wish I could tell people about the recovery system,” Ronnie commented. “It’s very cool!”

In the developing stages, Zipline considered using quadcopters to deliver the medical supplies. Ronnie said these aircraft were candidates because they are readily available. The company soon realized the downside. “They’re much more difficult to make waterproof,” he said of multirotors. “They also don’t have the endurance for the range that we need,” he said, speaking in terms of battery power.

A Zip aircraft is ready to be launched by a large compressed-air catapult mechanism. The flight testing for the aircraft and launching system was done along the California coast.

“A lot of development went into making those airplanes waterproof,” Ronnie stated about the Zips (which also have been called fixed-wing drones—a term that he does not like). The aircraft had to be built to fly in strong wind at high altitudes. The higher the airplane must travel, the more battery power is used, he explained.

Rwanda has unmanned aircraft regulations that are similar to those in the US. These include requiring unmanned models to be flown within line of sight. The Rwandan government, however, has made an exemption for Zipline. The Zips’ routes will be in areas that are designated as no-fly zones for other aircraft.

The autonomous Zip aircraft will have a set flight path, such as this one, that will be used to deliver medical supplies to clinics in Rwanda. The Rwandan government has made an exemption for Zipline to fly its aircraft in no-fly zones.

When Ronnie was first hired by Zipline, he was tasked with writing instructions for how to build the Zips, teaching others how to build and fly them, testing the motors and controls, and helping decide what components would be put into the aircraft. Ronnie said it was an honor to be an “RC guy” who was part of the company’s brainstorming sessions. “I’ve seen a lot of my ideas go into the [airframe],” he said.

Before the first Zip made its maiden flight in Rwanda, Ronnie was busy building as many airplanes as possible. “The goal we are working up to is [to have] 50 to 150 flights per day, 15 planes [flying] a day, and a whole lot of batteries,” Ronnie commented. He is also the Zipline’s safety pilot and watches how the airplanes behave in flight.

When Ronnie emailed Model Aviation about his new job, which he clearly loves, he wrote the following:

Ronnie enjoys having a career that allows him to build and test aircraft that could potentially save lives.

“Not only have I had the chance to do what I love, but I also have a chance to show the world that UAVs/drones can be used to do good, and to use my skills to save lives. Every day I see bad press for drones and worry about the result to the hobby I love. Taking this job was my way of trying to change the negative outlook and help in some small way to make it positive.”

The positive is definitely the work that Zipline is doing in Rwanda, which Keller hopes will soon expand to other countries.

“These supply chain challenges are not unique to Africa, and actually exist in countries around the planet. Our goal is to roll out Zipline systems in all of those countries to revolutionize how we deliver medical care to people who live in rural or remote locations,” Keller said.

“Zipline will ultimately allow the Rwandan government to put each and every one of the 11 million citizens of Rwanda within a 10- to 45-minute delivery of any essential medical product they could need.”

When the aircraft were ready to be launched, Zipline’s focus moved to Rwanda, and some of its employees were stationed there to get everything set up and running. “Our nest will be located close to a regional medical center there, just down the street from us,” Ronnie explained in April. “We will have a cold chain to keep the blood cool.”

The medical supplies come from the regional medical center, and then are sent out via Zip to other medical clinics and centers. Currently, motorcycles can navigate some of the rocky terrain, but Rwanda’s rainy season sometimes washes away roads with poor infrastructure, making them impassible for a motor vehicle. Delivering medical supplies via a motorcycle can take several days, Ronnie explained.

With the help of Will Hetzler and Keenan Wyrobek, Keller has built Zipline into what it is today. Will was his roommate at Harvard for three years, and he met Keenan through a mutual acquaintance in 2014. Keller explained how the idea for Zipline, which was formed in 2011, came about.

“We were spending time in several different countries in Africa, and realized that with the advent of cellphones, it’s now possible for doctors and health centers to text into a central system when they have a patient whose life is in danger, but they don’t have the medical product they need to help that person.

“But the other half of that system doesn’t exist. It’s not possible for the existing medical supply chain to respond quickly, even when they have the product that person needs. So we wanted to build that half of the system, and make it possible for countries to respond to emergencies quickly and efficiently, even when a patient lives in a remote or hard-to-reach location.”

Some of Ronnie’s coworkers earned degrees at prestigious universities, but had never flown a model aircraft. He was honored to be able to teach them how to fly.

In Rwanda, text messages are sent to the regional medical center near Zipline’s base. The requested medical supplies are then taken to Zipline to be delivered.

In 2010, approximately 58,000 women across Eastern and Southern Africa died during pregnancy and childbirth. The number of such deaths has slightly declined in the past few years, but getting more women access to the emergency care that they need is tricky in Eastern Africa. This is especially true in Rwanda, where the leading cause of maternal death is blood loss, according to a study by UNICEF.

In addition to mothers, children in Rwanda might no longer die from from malaria. Vaccines for malaria will be delivered by Zips, Ronnie said. “Which is just crazy because [malaria is] totally preventable,” he added. “They just don’t have the medicine.”

Ronnie said in April that he preferred to stay in California when the work in Rwanda began, but believed that he would be sent there for a short while. “I really hope that we’ll be a big success in Rwanda.”

In his email to Model Aviation, Ronnie summed up the reason that he decided to share his story.

“I’m sure it won’t change everyone’s outlook overnight, but seeing drones used to save lives all around the world might have an impact. It’s been an amazing journey to this point and only promises to get better—a dream come true for a guy who just loves Remote Control planes.

Zip airplanes have a hatch that opens underneath and releases a box of medical supplies that parachutes to the ground. The 22-pound Zip aircraft can fly up to 60 mph and are safe to catch by hand.

“I wanted to share the news to help spread the positive outlook for the future, at a time when we hear so much negative, and also to give hope to other hobbyist that dreams can come true. I have discovered that the old saying [about] when you do what you love, you never work a day of your life, is completely true!”

—Rachelle Haughn
rachelleh@modelaircraft.org

Sources

Zipline
http://flyzipline.com/product

Zipline video
www.youtube.com/watch?v=OnDpE8uSb7M

Written by Austin Axmann / Rick McCaskill / Jim Tiller
Camp AMA scholarship recipient, Western States Drone Rodeo, and 2016 Warbirds over Denver
As seen in the September 2016 issue of Model Aviation.

Here’s a picture and a few words from Austin Axmann, our third recipient of a scholarship to Camp AMA, thanks to your generous donations.

“Camp AMA was nothing but amazing. Everyone that was there was nice and willing to help. On the first day there was a midair and about six other crashes. There were other wrecks during the week, but not near as many as the first day.

“There were so many good things that came out of the camp. Many friends made and many planes learned about. I think the best night was when we were night flying. The pilots were great and the environment was beautiful (minus the cold). I can say that it was one of the most enjoyable weeks of my life. The experience was not comparable to anything I have done before.

“Special thanks to Troy Hamm and the RC Barnstomers for nominating me and to all that helped me go to Camp AMA.”

Circumstances would not allow me to attend the Drone Rodeo in Casper, Wyoming. Rick McCaskill, Colorado associate vice president (AVP), attended in my place and here’s his report.

The Casper Air Modelers (CAM) hosted the Western States Drone Rodeo at the club’s facility on June 18, 2016. This was the first FPV Rodeo, but the Air Modelers members hope it becomes an annual event.

CAM President Jeff Nelson said, “A big part of what we will do is show people that drone use by responsible pilots is fun and safe. We showcase the good things and want to get people involved with the recreational side.”

The setup included an FPV racingdrone layout, and an obstacle course featuring pylons and arches through which the drones flew.

Three drones at a time raced through the courses. We clocked 86 mph on one pass down the 400-foot straightaway. A big screen TV allowed the spectators to view the FPV of each competitor. There is video of the race below.

Bonus video

Casper Drone Rodeo racers (L-R) Chris Cohron; George Bob Hine; second-place winner Quentin Weiss; third-place winner Richard Sankey; Charles F. Thompson; Justin Webster; and Josh Nelson. First-place winner Greg Fleming is not pictured.

Thank you, Josh, and the members of the CAM for hosting this event and letting me take part. I was impressed by your city-owned facility and your great relationship with the Casper community. This was a great event to attend, and I met many of the club members and spectators. I hope I get a chance to attend again next year.

On June 11, 2016, I was able to spend the day at the annual Warbirds Over Denver event hosted by the Jefco Aeromod’lers. This year, as in most years, scores of pilots were registered. What a treat to see all of the great military stuff and watch it fly. Where else are you going to see an A-12 Shrike and a Nakajima B5N Kate torpedo bomber in the same pattern?

This year, Pete Thompson, club president, and the Jefco crew allowed me to use this event to host our annual District IX membership meeting. In the course of the day, I had the opportunity to chair a discussion with the assembled AMA members. At the conclusion of our meeting, Darrell Weidman won the drawing for a new Spektrum DX8 radio. Darrell is a deserving winner. He is he is a longtime Jefco Aeromod’ler and a committed volunteer for the warbirds event.

Jim Tiller presents Darrell Weidman with a new Spektrum DX8 radio at the District IX membership meeting. Colorado AVP Rick McCaskill assists.

Young Justin Brown, of Canon City CO, asked me if I would put his picture in the magazine. After being amazed by his knowledge of warbirds, military history, and his enthusiasm for this hobby, I gladly obliged.

Lots of great flying, good food, and great camaraderie are the hallmarks of this laid-back, longtime event. I hope I will get a chance to come back next year.

Thanks also to Colorado AVP Rick McCaskill for providing logistical assistance and helping out with the District IX meeting.

Written by Jim Mohan / Lawrence Tougas
12th Annual Arizona Electric Festival
As seen in the September 2016 issue of Model Aviation.

Bonus Photos

Superstition Airpark sits in the shadow of the Superstition Mountains of Lost Dutchman Gold Mine fame. Although no one found lost gold, more than 90 registered pilots and hundreds of spectators struck RC gold at the 12th Annual 2016 Arizona Electric Festival (AEF). Contest Director (CD) Shannon Gallagher, assistant CD Pat Gagnon, and their team executed an outstanding event.

The Arizona Model Aviators’ field includes an 800-foot asphalt runway with plenty of paved tarmac for airplane parking. A 250-foot long ramada provides plenty of space for airplane setup and congregating to examine others’ model configurations, new airplanes, and gadgets. With food service and generator-provided electricity to the wired ramada, the site is perfect for this event.

CD Shannon Gallagher and assistant CD Pat Gagnon conduct the morning pilots’ briefing.

Each morning, the tarmac filled with hundreds of electric-powered models of almost every shape, size, and description. After the daily pilots’ briefing, the flightline was full. While busy, lines for the flight stations were short. All who wanted to fly had ample opportunity.

The Saturday noontime show included a warbird gaggle, a 70mm or smaller jet gaggle, a helicopter speed demo, and demo flights from several of the vendors that had set up displays in the vendor area. A couple of models drew plenty of attention.

Clark Hans had several large scratch-built foam models. His Avro Canada CF-105 Arrow stood taller than he does!

It is powered by a pair of 90-millimeter ducted fans, each powered by a 10-cell battery pack. It was built from a combination of both pink and blue foam. It turned a lot of heads as it streaked by. Clark also had a large Concorde model powered by a pair of pusher propeller setups.

Clark Hans and his giant scratch-built Avro Arrow.

The owner-pilot team of Dale McCawley and George Kreyling flew a massive B-17 scratch-built from Bob Holman plans. The fully sheeted model is powered by four Power 46 electric motors from Horizon Hobby. The presence of this model, both on the ground and in the air, is impressive. With full-scale B-17s occasionally flying over the Phoenix area, it would be easy to do a double-take, mixing up this fine model with its full-scale counterpart.

Owner Dale McCawley and pilot George Kreyling prepare Dale’s Giant B-17 for flight.

Chris Picknally flew a couple of nice models. His foam Grob G 120TP trainer was a nice representation of the full-scale version. Powered by a four-cell battery and an FMS 4250 motor, the Grob 120 was a great-looking, snappy performer. Chris also flew a beautiful 90mm ducted-fan version of a Hawker Hunter. Done in Swiss yellow and brown tiger stripes, the large 1950s-era jet turned more than a few heads as it flew by.

Chris Picknally returns his Hawker Hunter to the pits after a successful flight.

Jerry Festa had a couple of models he’d recently reviewed online. He had a blast with the Tower Hobbies Wilga 2000 from Origin Hobby and the new Flyzone Seawind EP. One of his Wilga 2000 flights was done almost entirely with the flaps down. He demonstrated the excellent slow flight characteristics and the outstanding short field takeoff and landing capabilities of the little blue high-wing airplane. This captures just a few of the aircraft on the tarmac.

Jerry Festa and his crewman ready the Wilga 2000 for flight.

The Arizona Electric Festival is primarily a fun-fly. This year, as in years past, it has drawn people from across the Southwest. If you’re looking for fun, flying, and fellowship with lots of great models and an excellent site, you need to put the 2017 AEF on your calendar.

My thanks to Jim Mohan for this month’s column. Until next time, I wish you nothing but happy landings.

Written by Mike Hurley
A people meet with airplanes
Event coverage
Photos by the author
As seen in the September 2016 issue of Model Aviation.

Bonus photos

Bonus video

The entire week, while visiting the Triple Tree Aerodrome near Woodruff, South Carolina, I kept asking myself, “How would I describe the Joe Nall experience?” It nearly defies description. It can be laid out in a few words and stats, but does that adequately describe the event? One thing is certain, Joe Nall Week has evolved into a unique RC gathering that crosses boundaries as no other event does.

Not only do enthusiasts from nearly every segment of flying participate, but other RC disciplines such as cars and boats show up in certain areas of the more than 400-acre site. While I was there I saw sailplanes, warbirds, helicopters, scale helis, sport jets, scale jets, military jets, corporate jets, commercial jets, scale airplanes, sport airplanes, turboprops, aerobatic aircraft, 3-D airplanes, float airplanes, Control Line (CL) models, electric, gas, glow, and turbine engines—engines of so many configurations that I couldn’t possibly name them all.

The event started, as most do, in a very humble way. It was a local Giant Scale fly-in, put on by two friends who shared their love for model aviation. The first meet was in 1983. Pat Hartness hosted the event at his personal flying site and Joe Nall ran the event. Joe continued to emcee the event until he died in a tragic airplane accident in 1989. In 1990, the event was renamed the Joe Nall Fly-In. Today it’s known as Joe Nall Week.

The event has grown exponentially since its inception in 1983. Each year, Pat adds to or improves the flying site. There are now at least five separate flightlines, including the main flightline, the pond for float flying, an electric-only field and a 3-D electric field, along with the wild and crazy Giant Scale 3-D line. There’s also an area with three CL circles and a helicopter and multirotor flightline. This year there was a special FPV obstacle course.

Camping, RV spaces, and facilities also seem to expand every year. A few years ago, showers and a gazebo were added at the 3-D line, and then later a charging station was constructed near the electric line. This year, the crew built small pilot stations that jut out into the pond for better access to float airplanes.

With more than 400 acres of space, there are five RC flightlines to choose from at the Triple Tree venue, including a huge pond for float flying. This year, small separate pilot station jetties were added to aid in launching and retrieving watercraft.

A new building is going up that will house a learning center with full-scale and RC flight simulators and other educational facilities. This year, the vendor row was unified in a central location, making RC shopping much more convenient for those who come to the event just for that.

I love coming here to buy airplanes and equipment because this is the one place where you can see, and even test, equipment firsthand from a number of manufacturers, including Giant Scale airplanes that most local stores can’t have in stock. I got to test-fly a 35% Extreme Flight Yak 54 on the 3-D flightline.

I’m not sure if anybody has researched large RC flying events, but I’d guess it’s safe to say that Joe Nall Week has become the world’s largest RC event. According to the staff at Triple Tree, there were more than 1,700 registered pilots at this year’s event, held May 7-14. Along with spectators, friends, and not counting the crew and workers, more than 13,300 people came through the gates.

I don’t know how many aircraft were there, but because every pilot seemed to bring two or more, I’d estimate the number is well into the thousands. Pilots came from 42 states and nine countries, and at any one time there could be as many as 40 aircraft in the air. I’ll bet that no one saw that coming back in 1983!

These statistics are interesting, but they don’t begin to give you the feel of attending the Joe Nall Week. As I walk from flightline to flightline, I continue to wonder how to describe the event. There are hundreds of people here from disciplines that would not normally be seen flying together, yet everybody is getting along famously and enjoying each other’s company.

Austrian champion Gernot Bruckmann flew an aerotow-launched scale sailplane during the noon demonstrations. Gernot has a retail RC dealership based in Austria.

In addition to the RC flightlines, there were three CL circles at Triple Tree. There is where we met 8-year-old Layla Barry from Grovetown GA, flying with her dad. Layla has been flying CL since she was 3 years old. Anyone could take a demo flight on a CL airplane, and both the author and his wife gave it a go.

The main flightline is crowded with canopies packed together leg to leg, and everybody’s happy to have you set up beside him or her. I wasn’t there early in the week so I had to set up my space behind another pilot. When I arrived, I asked if he would mind if we joined them and by the end of the week I was good friends with all of those around us; this starts to hint at what the Joe Nall event is.

There are so many people here. All of them have a story, and all of them have a gift—some of them have the gift of piloting skills, others are builders, and all are modelers and enthusiasts. That itself is a gift.

Some of the more notable pilots or aircraft owners were asked to put on a show at the main flightline each day at noon. I was able to watch parts of the shows on three of the days. The performances were surprising and many were downright astounding. The noon demos at Joe Nall Week will remind you that even in a hobby you’ve been involved in for years, you still haven’t seen it all.

Each day at noon, the main flightline is closed for demonstration flights and huge crowds gather behind the pit area. Top pilots from around the world come to Joe Nall Week to be a part of the noon demos. Many of these pilots represent manufacturers and are here to show their products, some come to debut new innovations, and others demonstrate extraordinary skill levels.

The Jeti USA Girl Flight Team showcased two young women, Aneta Bouskova and Ashleigh Heath, flying 3-D aerobatics. Each day crowds gathered around the main flightline at noon to watch professional teams, pilots, and manufacturers demonstrate their skills and their products.

Every year, those on the cutting edge of our hobby continue to push boundaries and defy what we previously thought were limits of flight and performance, and it’s all here to see firsthand at Joe Nall Week.

One of those pioneering people is RC Aerobatics World Champion, TOC Champion, aircraft designer, and innovator, Quique Somenzini. Quique is part of a new company called Flex Innovations that brings new aircraft, electronics, and flight systems to the RC hobby. Quique demonstrated Flex’s new F-16QQ 3-D turbine jet that has been highly specialized with extreme light weight, a high-angle, thrust-vectoring nozzle, extreme control throws, and more design features to create a jet that performs precision, high-alpha, and post-stall maneuvers as never before. Quique’s performance was nothing short of pushing the known flight envelope into new territory. What would you expect from the man who many credit with inventing 3-D flight?

On the left is the man responsible for creating the Triple Tree Aerodrome and the Joe Nall event, Pat Hartness. Pat congratulates world-renowned pilot and aircraft designer Quique Somenzini after another cutting-edge demonstration flight.

During the past eight years, the Joe Nall event has hosted a public building project called the Valkyrie, based on the 1937 Carl Goldberg model of the same name. The build was set up in Pat Hartness’ personal hangar and only took place during Joe Nall Week. Anyone attending the event was invited to sit down and work on the airplane. More than 1,000 people helped in the build. In fact, I helped build a couple of wing ribs two years ago and I’m sure that a good many of you reading this have also pitched in on the project.

The giant Valkyrie flew in Thursday’s noon demo in graceful style and has been a complete success. Next year, Pat wants to fly the Valkyrie for 48 hours during the Joe Nall event with the idea of soaring during the day and using gasoline at night. He is looking for engineering help to design the needed propulsion system. If you think you can help make this happen, contact the staff at the Triple Tree Aerodrome.

This year saw a flight of the public-built scaled-up giant Valkyrie, based on a 1937 Carl Goldberg design. This aircraft was built during an eight-year span by attendees of the Joe Nall event and completed in 2015. The electric-powered Valkyrie has a 20-foot wingspan.

Two other demos that helped me define Joe Nall Week were a turbine-powered, 5-meter sailplane that could reach 200 mph and perform amazing precision aerobatic maneuvers, and the Legendary Fighters, a nine-member team of warbird enthusiasts that traveled from Germany to perform a precision choreographed team flight with World War II aircraft from many of the war’s combatants.

This year, it seemed that many of the noon demonstrations featured team formation flying or coordinated performances. These two giant 42% Extras were flown by Gernot Bruckmann and Markus Rummer. One aircraft is gas powered and the other electric.

Giant Scale takes on another dimension with this 14-foot-long Airworld Models F-104 Starfighter flown by Ali Machinchy. Ali works for Horizon Hobby and is one of the premier demonstration pilots at Joe Nall Week. The aircraft was built by Trond Hammerstad from Norway and uses a single BF-Turbines B300F turbine.

Aside from the talent invited to perform the demos were untold numbers of brilliant attendees, from the man pitting next to me with mind-boggling, complex, cutting-edge computer systems designed to automatically trim his airplane under every circumstance, to 14-year-old Kobe Cantin on the 3-D flightline, who flew with grace, skill, and maturity well beyond his years, to designer/builder Chuck Gratner who designed and scratch-built his own vision of the quintessential 1930s-era Golden Age air racer that he named the Riley Model B.

This is one of two stunning, hand-built aircraft that came from the mind and skilled hands of Chuck Gratner. The design is a mixture of Chuck’s favorite Golden Age aircraft that he dubbed the Riley Model B.

Joe Nall Week is, as you might gather, a huge event with something amazing happening along the flightlines all day and night. I certainly couldn’t see it all, or even report a small fraction of it, but I can tell you that as my wife and I sat on the lawn outside of the hangar during the barbecue dinner, listening to a live jazz concert and watching the sun set while surrounded by 1,000 or so of our fellow modelers, we both looked at each other and said, “We must be livin’ right because this is just about as good as it gets.”

Even with all of these stories, and the stats, and the enormity of it all, the Joe Nall event is hard to describe. But on Friday, the event’s emcee and rambling “Mouth of the South,” Bob Sadler, wrapped it up nicely in his description of Joe Nall Week. He said, “It’s not an airplane meet. It’s a people meet that just happens to have airplanes.”

—Mike Hurley
mhurley222@twc.com

Sources

Joe Nall
www.tripletreeaerodrome.com

Riley Model B
www.gratnerbrothers.com

GB-Models
www.gb-models.com

Flex Innovations
(866) 310-3538
www.flexinnovations.com

Written by Paul Kohlmann
Photos by the author
As seen in the September 2016 issue of Model Aviation.

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Construction Article

When introduced in 1935, Willy Messerschmitt’s Bf 109 was nothing short of revolutionary. Luftwaffe pilots were initially wary of the high wing loading, the side-hinged canopy, and the narrow track of the
landing gear.

Some of their fears were well founded. For instance, the landing gear arrangement that greatly simplified manufacturing and maintenance also contributed to thousands of accidents. But after pilots such as Ernst Udet embraced the little hot rod, the Bf 109 began shattering speed and agility records at the great prewar air meets of Europe.

By 1945, the Bf 109 was the preferred mount of many of the Luftwaffe’s top aces, including the highest-scoring ace of all time—Erich Hartmann, with 352 victories. Repeatedly upgraded, the 109 was in continuous production throughout the war. Nearly 34,000 were completed, including license-built models in Spain and Czechoslovakia—more than any other fighter in history. Incredibly, the last operational mission for the Bf 109 was in 1967 in the same Spanish skies where it first saw combat in the 1930s.

The early variants of the 109, from the “V” prototypes through the Bf 109E or Emil, can be distinguished from the later marks by their square wingtips. The earlier variants also tended to be aerodynamically cleaner, as various bumps and bulges were added from the Gustav onward to accommodate the heavier weapons that they carried. Many builders prefer the battle-hardened Gustav, but I find the earlier variants sleeker and more appealing.

If the clean lines and historical significance of the Bf 109 aren’t enough of an attraction, there are also myriad paint schemes for consideration. These range from the aircraft of the Condor Legion in Spain, to those that battled over France and Britain, and to the aircraft stationed in North Africa. If front-line schemes don’t turn your crank, there were several colorful, polished, prewar racers that are bound to turn heads at the field.

The Plans

Several years ago, I designed a park flyer model of the early Bf 109 with a 30-inch wingspan. The design was in the Free Flight style—stick-and-tissue-type construction with lightweight electronics. To keep things simple and lightweight, this little Messerschmitt was a belly lander without any landing gear.

This 30-inch 109 flew so well that I scaled up the design to a 45-inch wingspan. The enlarged version retains the same structure, but with some upgrades. Because the heavier 45-inch model would be more prone to damage on a belly landing (that big chin scoop is dying to eat up some dirt), the wing was redesigned to include accommodations for servoless retracts.

The bigger plans are introduced here as a free download from Model Aviation’s website. Like the 30-inch Bf 109, the 45-inch version is available as a short kit with a plastic canopy and front cowl. The kit includes parts to build the larger chin scoop of the A through D models.

The 45-inch plans also include outlines for the chin and underwing scoops of the Emil, should the builder choose to model this variant. For builders who prefer to cut by hand, the parts’ outlines are included as a second sheet to the plans.

The construction of the 45-inch Bf 109 will be the subject of this three-part series. We’ll get through most of the framework in this article and move on to the internals in the next installment.

Construction

The design of this model and the techniques used to build it are very similar to the Miles M.20 that was covered in detail in last year’s “Construction Series.” This series will continue in the same fashion. I’ll spend more time on general balsa-building techniques than the traditional step-by-step build instruction format.

For techniques already discussed in detail, I’ll refer the reader to a “Construction Series” article when appropriate. These articles can be found on the Model Aviation website.

Tail Group

The tail of the Messerschmitt builds up exactly the same as the Miles M.20. The process begins by soaking 1/16 x 3/16 balsa strips in water overnight. After the balsa is flexible, the strips are stretched around a form to create the outlines of the tail parts.

Tail group outlines were created by laminating softened balsa strips around a foam-board form.

Complete the lamination by gluing three layers, one against the other. After the outlines have completely cured, they can be removed from the forms. Although they appear fragile, these laminations are strong and lightweight.

Assemble the tail parts from the kit over the plans and then fit the cured outlines into place. Cut strips of 3/32 balsa for the bracing that goes between the short kit parts and the laminated outlines.

The rudder and elevators are built-up from 3/16 balsa, while the fin and stabilizer are built from 1/8 balsa. Sheeting the thinner stock on the fin and stabilizer with 1/32 balsa will build these parts up to 3/16. The rudder and elevators will be left as open structures. This procedure does a good job of replicating the construction of the full-scale 109, which used fabric-covered control surfaces on an otherwise aluminum-sheeted structure.

Strip stock for bracing the framework was cut from the kit’s sheet wood with a balsa stripping tool.

For hinging models of this size, I’ve become a fan of Robart hinge points. One reason for this is that the hinge pivot point can be moved back into the leading edge of the control surface. This allows a builder to minimize the gap between the fixed and movable surfaces in the same way that is typically done on full-scale aircraft.

The offset hinge point and a little extra sheeting on the fin hide the rudder gap.

Now that the tail group is shaped and hinged, it can be set aside until it is time for covering.

These processes are explained in more detail at http://ModelAviation.com/m20tail.

Fuselage

The fuselage construction begins by building the left side over the plans. Get started by preassembling formers F6 through F8, and the two side keels K5 and K6 over the plans.

Now pin the vertical keel parts K1 through K4 to the plans. Join these parts together by gluing in the left half of each of the formers F2 through F9. Note that the top half of F3 is tilted backward. This will make it easier to remove the battery hatch later.

There are a few parts that need preassembly before the real fuselage construction can begin.

Tie all of the formers together with the preassembled side keel K5/6. Now install the wing saddle. Dampen the outer side of the saddle with a little water and it will begin to curl. Glue it to formers F3, F4, and F6. Add a few stringers to stiffen the fuselage assembly and then let it cure completely before removing it from the board.

Now that the keels, formers, and saddle are in place, it’s time to add a few stringers.

The right side of the fuselage is built free of the building board. Begin by gluing the battery tray, wing pin plate (WP), and wing bolt pad (WB) to the left side assembly. Now glue the right half of each former to its left-side counterpart. Small spring clamps are handy for pinching the former halves together so that they are parallel to one another.

Add the side keel K5/6, the wing saddle, and a couple of stringers. Now it’s time to move on to the battery hatch.

Clamps hold the right side formers parallel to the left halves.

Battery Hatch

Construction to this point has been simple. Building a removable battery hatch isn’t any more difficult, but it is important enough to deserve a section of its own. The following process applies to access hatches in many different models.

The parting line for the hatch is formed between doubled formers at each end of the hatch, and a pair of horizontal rails. The order in which the hatch parts are assembled is important. If the rails that form the lower parting face of the hatch are installed first, it will be almost impossible to get the hatch formers into their notches.

Glue the three hatch formers into their notches in the upper keel. Be careful not to glue the front and back hatch formers to their adjacent fuselage formers. Inserting pins between these parts as shown will prevent the formers from sticking and maintain an even parting line.

The rails that frame the edges of the hatch go in after the formers. Slide the bottoms in first, and then the top.

Hatch formers are glued only to the upper keel. Pins maintain a gap between the hatch and the fuselage formers.

Now the hatch rails can go in. Slide the lower rails into place first and glue them to the notches in the fuselage formers. Now fit the upper rails, but glue them only to the hatch formers. Use a few pins in the former parting lines to create an even gap, and to keep the corners of the hatch from sticking to the fuselage opening. If done in this order, this should be a hassle-free operation. Strengthen the hatch by adding a fillet of glue to the corners of the hatch rails and formers.

Now the time has come to get to stringing! Remove the pins between the hatch formers and add the stringers, working from side to side. Keep a close eye out for warps as you go. Installing the stringers and using balsa infill to strengthen key areas are covered in depth in the “Construction Series” fuselage article (http://ModelAviation.com/m20fuselage).

After all of the stringers are in place, sand the entire fuselage. Most of the stringers can stand slightly higher than their formers. This helps to minimize wrinkles later when the covering is pushed up by the formers. The stringers at the ends of the hatch must be sanded flush with the formers. If not, wrinkles will form when the covering is stretched at each of the high spots.

Now it’s time to cut the hatch free. By now, the completed and sanded fuselage should be a thing of beauty. Many builders are intimidated to take a knife or saw to their handiwork, but it must be done.

Carefully cut the upper keel and each stringer between the doubled formers at the front and back of the hatch. Take your time and be careful to cut only the stringers and not into the formers. If care was taken with the glue, the hatch should pop free without much trouble. If not, carefully cut through any excess glue and pry gently with a wide blade until the hatch can be removed.

Free the hatch by cutting between the doubled formers with a sharp blade or razor saw.

A combination of a pin in the front and magnets in the back is a nice way to hold the hatch in place. The pin will keep the front from lifting in flight while two pairs of rare-earth magnets, available from K&J Magnetics, allow the hatch to be snapped on and off. The pin can be a bit of wire or dowel. Strong, but tiny, rare-earth magnets are available in many shapes and sizes at your hobby shop or online. Two pairs of 1/16 x 1/8-inch diameter magnets were used on the Bf 109 prototype.

With the hatch framework in place, drill a hole through the plywood front former and into the front of the hatch for the pin. Now drill holes through the hatch and fuselage rails for the magnets. Drilling guide holes in the rails before the stringers go in makes it easier to align the magnet holes later.

Use your choice of glue to hold the pin into place in the front of the hatch. I use epoxy on the magnets. A neat trick for this is to put a small piece of waxed paper between each pair of magnets. Coat the holes in the rails with epoxy. Now drop the magnets into place in the lower rails.

The front pin is in place and the rear magnets are ready for epoxy.

The waxed paper will keep the magnets from falling through and prevent the rails from sticking to one another. This method will also ensure that the polarity of the magnets is correct. Getting that backward is not cause for celebration.

Carefully fit the hatch into position. The upper magnets should slip into their holes in the hatch rails. Clamp the hatch into position and brush a little epoxy over the exposed faces of the magnets and the surrounding areas in the rails. After the epoxy is cured, the hatch should easily pop on and off.

Here’s the fuselage with all of the stringers in place and the tail loosely fitted. Next on the punch list are wings and retracts.

In Closing

It’s been great to hear from builders who downloaded the free Miles M.20 plans last year. So far, the only complaint has been from a few builders who found that the short kit parts didn’t quite fit the plans because they had printed them at the wrong scale.

If you decide to download and print either of these plans, please make sure to print at 100% scale. You can double-check the scaling of the print by measuring the 4-inch rulers in the lower left corner of the plans.

See you next month when we frame up the Bf 109’s wing and install the retracts.

—Paul Kohlmann
ptkohlmann@aol.com

Sources

RetroRC (45-inch Bf-109 short kit)
(248) 212-9666
www.retrorc.us.com

Manzano Laser Works (30-inch Bf-109 short kit)
(505) 250-1540
www.manzanolaser.com

Robart Manufacturing, Inc.
(630) 584-7616
www.robart.com

K&J Magnetics, Inc.
(8880 746-7556
www.kjmagnetics.com

Previous installments (Building the Miles M.20)

Installment #1 (Toolbox basics)	Installment #5 (Building the tail group)	Installment #9 Casting detail parts
Installment #2 (Balsa builders' parlance	Installment #6 (Building the fuselage)	Installment #10 (Waterslide decals)
Installment #3 Reading plans	Installment #7 Building the wing	Installment #11 (Wrapping it up)
Installment #4 Workflow planning	Installment #8 Polyspan and paint	Download all installments (.zip format - 46MB)