By Jon Barnes. Small in size, big on performance. Photos and video by Jon Barnes. Full review in the Summer 2015 Park Pilot.
Specifications
Type: 3-D aerobat Skill level: Intermediate Wingspan: 22.2 inches Length: 24.4 inches Weight: 8.8 ounces Price: $179.99 Info: horizonhobby.comFeatures
• Visually striking, 280-size clone of the full-scale Viking Model 12 • AS3X technology delivers rock-solid handling • Spektrum AR6335 DSMX six-channel nanolite receiver (installed) • Powerful 280-size brushless motor (installed) • Four 3.5-gram digital super submicro servos (installed) • 3-D-size, double-beveled control surfaces (installed)The E-flite Viking Model 12 is based on the full-scale biplane flown by Scandinavian Airshow pilot Jacob Holländer. Jacob campaigns his brilliantly colored Viking in air shows worldwide. Many of his aerobatic maneuvers are performed at extremely low altitudes. E-flite’s exciting, 280-size high-performance rendition of the Viking should make pilots eager to get this model assembled and in the air. This foam-composition model features the same eye-popping blue and yellow paint scheme as the full-scale biplane—including the cartoonish Viking caricatures on the fuselage. The model also sports an array of sponsorship graphics. Noted aircraft painter, Mirco Pecorari, is the artist behind the airbrush. Rigid foam helps recreate the compound curves of a Model 12 biplane. The teardrop-shaped wheel pants and two-tone blue/yellow spinner are plastic. Carbon fiber reinforces the lightweight airframe. An 1,800 Kv brushless outrunner lurks inside the nose of the E-flite airplane, with a 10-amp speed controller and six-channel Spektrum receiver mounted underneath the removable hatch on top of the cowl. As a BNF (Bind-N-Fly) version, pilots will need a 3S 450 mAh LiPo battery and DSM2/DSMX-compatible transmitter. Spektrum’s AS3X stabilization system comes embedded in the AR6335 six channel nanolite receiver, which drives four E-flite submicro 3.5-gram digital servos. The large control surfaces are prehinged. Both the top and bottom wings are equipped with ailerons, with a short pushrod joining each pair. The only item absent in this smaller electric version of Jacob’s biplane is the smoke system! One observation, made after initial examination of the individual airframe components, was that the aesthetics of the paint used was not up to my expectations. The paint used on much of the model does not fill the “grain” of the foam, leaving small craters where the paint did not penetrate. This is most obvious on the wings, resulting in a slightly mottled appearance. Although noticeable on the bench and flightline, I ceased to be concerned about it after the model took to the skies. It is hardly visible from a few feet away. The vibrant little Viking looks fantastic in flight. Although it is a smaller model, the Viking is not a member of the micro-size UMX family of models. Unlike the UMX aircraft, this slightly larger 280-size model does not come out of its box fully assembled. Basic assembly involves gluing the two wings and supporting struts and cabanes in place using foam-safe cyanoacrylate adhesive. I used accelerator to expedite the cure. After the two wings are glued in place, disassembly is not possible, so storing and transporting this airplane in its shipping box is not an option. Total assembly time, which included shooting some studio photos of it, was roughly two hours. When mounting the bottom wing to the fuselage, a pair of hemostats makes it a cinch to grab the aileron servo leads and work them forward toward the receiver. Accessing the receiver and flight battery is simple, thanks to the relatively large, magnetically retained removable hatch. The aileron servos must be plugged into the included micro-size Y connector and then connected to the appropriate channel on the receiver. This is necessary to satisfy and properly enable the embedded AS3X technology. The connectors used on these submicro servos are small; treat them with care when plugging them into the Spektrum nanolite receiver. I placed the recommended 3S 450 mAh battery all the way forward in the battery compartment in order to hit the recommended CG (center of gravity). Spektrum’s latest AS3X-equipped receivers, including the AR6335 nanolite six-channel receiver preinstalled in the Viking, are programmable. Most modelers may be accustomed to setting dual rates and exponential values in their transmitters. Spektrum has moved much of the programming normally done in the transmitter into the receiver. The Viking’s AR6335 receiver comes preprogrammed with two flight modes. The programming recommendations in the Viking’s assembly manual explain that a pilot should configure a switch on the transmitter to select either the Precision Flight Mode or 3-D Mode embedded in the receiver. These flight modes are configured specifically for the Viking and include preset control surface throws, exponential, and AS3X system gains. The Precision Flight Mode features low rates and AS3X gains and is intended for performing non-3-D-style aerobatics. The preprogrammed control surface throws in this mode are definitely on the tame side. The 3-D Mode is configured to use higher rates and AS3X gains and is touted as delivering “extreme maneuverability and maximum stability.” The control surface throws in this mode are extreme. The rudder is configured to deflect to its maximum mechanical travel and stops just short of coming into contact with the elevators. What a pilot needs to take away from this is the need to start with a fresh, new model in the transmitter when configuring the Viking. All rates should be left at 100%, with exponentials at zero. Subtrims and trims should also be left at zero. This last requirement is a prerequisite of the embedded AS3X technology. If it is necessary to adjust the control surface neutral positions, the AS3X technology performs best if only extremely minor trim adjustments are made. Changes to the receiver’s preset values can be made by obtaining the optional receiver programming cable and free Spektrum programming application. Alternatively, the Viking’s manual comments that minor rate and exponential adjustments can be made in the transmitter programming. As I was configuring a flight mode switch in my transmitter, the Viking’s speed controller started randomly and repetitively beeping out the same series of tones emitted when it is initializing. I immediately noticed that it was hot to the touch. I quickly removed power, allowed it to cool for a few minutes and then reconnected the flight battery. Although it did initialize, advancing the throttle resulted in only a temporary burst of motor rpm. The ESC then ignored the throttle stick and completely failed a few seconds later. I grabbed a replacement ESC from another model and finished configuring the Viking. While checking the elevator throws, I noticed that the two elevator halves were not perfectly aligned with one another. I carefully deflected the two halves, gripping both of them on top of the embedded elevator connecting rod, until they were properly aligned.
This is a small parts count ARF kit, with minimal assembly required.
The authentic blue and yellow Viking paint scheme offers excellent visibility. Control surfaces have plenty of throw for 3-D flight.
The Viking’s first flights were made using Precision Flight Mode. The assembly manual suggests this approach, and my limited 3-D skillset validated that this was the way to go. The benefits of the AS3X stabilization technology are manifest as soon as the takeoff roll begins. As it accelerated down the runway, this little tail dragger showed no tendency to ground loop. It was amazingly easy to hold it on the centerline. With 80 watts (static), or nearly 150 watts per pound worth of performance on tap, the 280-size brushless power system rapidly gets this aerobatic biplane to rotation speed. This amount of power also provides good vertical punch out in the hover. Although the control surface throws programmed into the Precision Flight Mode are slightly small, they provide sufficient authority to crisply perform a variety of standard aerobatic maneuvers. Knife-edge flight, loops, inverted flight, and snap rolls can easily be done when in Precision Flight Mode. The AS3X makes this 8-ounce model feel and fly like an 8-pound airplane. The stability and smoothness of the Viking in flight is superb! With the throttle boosted to 100%, the Viking climbs out vertically with gusto! When it is time to bring this agile little aerobat back to earth, it is best done with a little power held all the way to touchdown. After a few conservatively timed 5-minute flights, the flight battery was barely 50% depleted. Having explored Precision Flight Mode, it was time to shift to the more aggressively configured 3-D Mode. With a fresh 450 mAh pack inserted, I sent the Viking up and flipped the flight mode switch to 3-D. The extreme control throws, the respectable amount of power, and the stabilizing influences of the AS3X are a veritable triple play of 3-D goodness! Although my 3-D skills are still a work in progress, I was impressed with how easy it was to hang this biplane on the propeller in a hover. Getting out of trouble is as easy as gunning the throttle and keeping the nose pointed skyward. Low-speed, high-alpha flight is stable and sure. The AS3X system does a good job of minimizing a newer 3-D pilot’s workload. With ailerons present on both the top and bottom wings, the Viking’s roll rate in 3-D Mode is insanely fast. I did notice a little control-surface oscillation would occasionally creep in if the model built too much airspeed in this mode, but the manual expressly warns about this and advises that Precision Flight Mode should be used for higher-speed flights.
The Viking is at its best when flown in the 3-D Mode. The AS3X system gives it impressive low-speed stability.
TIn the aerobatic flight mode, the Model 12 responds very well to even small control-surface deflections.
The E-flite Viking Model 12 is capable of satisfying a variety of pilots. Those who enjoy performing basic aerobatic maneuvers and scale flying will find that the Viking is a classy little park-flyer-size replica of an authentic airshow airplane. Flights made in Precision Flight Mode keep performance on the tame side. Intermediate-level pilots who have any desire to develop their 3-D and extreme aerobatics skills will be attracted to the confidence-inspiring effects of the AS3X stabilization system. It definitely lightens the overall workload inherent to complex 3-D maneuvers. Pilots who have not experienced the AS3X system may find that this model is the perfect airframe with which to experience its capabilities. Those who are 3-D proficient are sure to love the Viking’s wild side. Flip the flight mode switch to 3-D and this boldly colored biplane can execute maneuvers that are even more insane and exciting than those performed by Jacob Holländer himself!
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