Ultra in the Snow - Flights 2 and 3
I didn't think I'd get any more flying with the Polaris Ultra in 2012, as the forecast was for cold and breezy conditions. But it turned out quite nice -- -7C and snow but no wind.
So I got to make flights 2 and 3. And this time my usual camera person came along. It was a great session!
The Ultra is wonderful to fly.
I had increased the throw on elevator and rudder since flight 1 and also moved the CG back to the step. It was just right. Ultra lifted off easily, flew very smoothly and had all the elevator needed for any kind of landing for skimming in at speed to slowing right down to "plop" onto the snow.
Aerobatics were very good with rolls axial and needing only a small amount of down when inverted. Likewise, inverted flight was easy and smooth with only moderate down needed to maintain height. Loops were easy and round.
The model handled beautifully in the circuit, with no excessive nose dropping in turns or twitchiness on aileron. The landings were as easy as any I've done. And with increased rudder throw Ultra turned easily in the snow (unlike the first flight, when it didn't have enough throw).
The video shows all of this. What it doesn't show is the slow flight phase. I wasn't sure how Ultra would do at high alpha, as it has somewhat higher wing loading than the regular Polaris. The answer is that it's great at low speed. I flew around for a minute or so while holding full up and it was perfectly controllable and well behaved. There wasn't even the usual wing rock. And the transition back to normal flight was very easy, with no altitude loss.
I was flying with the standard motor (Suppo 2810-9) with 8x6 three blade prop by Master Airscrew. The battery was 3s 2200 30C. While I will be trying it with 4s, my sense now is that a decent 3s battery is more than enough for normal flying (unless you insist on true vertical climbs).
I could hardly be happier with the way Ultra flies. Rating five out of five.