Spring has sprung here in the mountains of northern Utah!
The Rafale goes together really quick. From the box being delivered to my porch to being ready to fly was less than :30 min. The finish is great, but the paint scheme is LOUD. This isn’t necessarily a bad thing though as I fly late into/after sunset and the scheme helps with orientation.
I set the aircraft up in my transmitter as a normal wing with aileron and flap. The internal mixing board handles the rest. (See my included picture for flap rates and settings.) Position 0 is flaps up. Position 1 is approach flaps. Position 2 is landing flaps. At approach flaps, I have 18 units of nose up elevon and canard compensation. At landing/full flaps I have 24 units of nose up compensation. I have the book high rate elevator for landing with the flaps, and use book medium rate for landing without flaps, more on that later.
I have book low, and high settings for aileron, elevator, and rudder. I also have medium rates in the middle of those.
For the maiden flight I went with low aileron and medium elevator rates, with a Roaring Top 5000mah 70C pushed all the way back, she flew perfectly. Flight time was 3:30 with 3.7v/cell.
I fly off a long smooth asphalt strip, and 200ft into the takeoff roll she smoothly rotated and lifted off. The takeoff speed was fast, but i was trying to avoid the pop off the ground others had demonstrated on early YouTube videos from Asia. With the 5500mah Roaring Top pushed all the way back, the CG sits in the aft half of the recommended range at 125mm from the reference mark. Roll was about right without flaps, but pitch was just slightly sensitive at this CG on medium rates with 40% expo for both.
The model is moderately fast in the 105-110mph range, but the airframe is draggy. She slows quickly even without ordinance drag, and even more so with. She has a beautiful Airframe howl above 80% power at speed, and will cruise comfortably in the clean configuration with 50-60% power on a good battery.
Stalls were accomplished gear up and down, they were pretty tame without rapid pitch or wing drop unless doing an accelerated stall. Gentle stall entry with rudder work gives a nice falling leaf descent without wing drop at full aft elevator.
Flap deployment was smooth at approach and landing flap settings with no pitch up or down when configured per my settings. The model will rapidly sink below half power once flaps have been deployed at approach settings, and even more so at full. The flap “crow” setting built into the mixing board puts the elevons down on the inner surfaces and up on the outer surfaces to act as flaps. This functions as a flap but also a speed brake, with the canards deflecting up to compensate for nose down pitch. In the real aircraft this allows the jet to have the motors spooled higher which the Rafale uses for carrier ops.
CAUTION CAUTION CAUTION
Because of how the mixing board deploys the flap function, you have less pitch authority once they are deployed. I found myself running out of pitch authority as soon as I slowed to a speed closer to where a lighter model would have been ok, especially on my medium elevator rates. Post maiden flights showed that landing with approach and full flaps required HIGH elevator rates to have adequate pitch authority to flare for touchdown unless landing very fast. The model lands fine on MEDIUM elevator rates without flaps in a nice nose high flare at a SLOWER speed than with flaps.
Takeoffs were accomplished clean and I also tried half flaps. With half flaps the takeoff roll was longer and needed a much higher speed to have pitch authority to rotate. This was tried on medium and high elevator rates. On high rates she will rotate faster, but rapidly pops off the ground once the speed is high enough to get pitch authority. Probably suitable to grass ops, but the takeoff is very unscale.
The 80mm Rafale is a beautiful model. She is no speed demon but is powered well. The model is heavy for its size and doesn’t float or high alpha the way the Freewing Gripen will, but this was expected with the weight difference. I test flew everything from a 6000-4000mah battery with 15 flights on the maiden day. Lighter batteries of course give the aircraft more acceleration and vertical, and let it fly a little slower and high alpha a little better with the lighter wing loading. I flew 6 different brands of batteries in her and the best performing was the 4400mah 70C Roaring Top. It’s the right punch for the weight and the sweet spot on this model. Aft and Forward CGs were all attempted too. Aft becomes squirrelly in pitch and roll even at medium rates, and forward requires a lot more pitch with HIGH elevator rates.
The mixing board is well done and the flap function is fun to play with, but again, the model actually lands slower without the flaps. CAUTION CAUTION CAUTION again, the flap function requires higher power and speed even at aft CG ranges or you will run out of pitch authority before you’re on the ground even with High rate elevator.
Overall a fun and well executed model.
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