It was quite a nice morning again this week, so there were lots of people flying. There was a guy on a bike with a 150 sized drone (no FPV), flying loops and rolls when I turned up. Also, the DJI Inspire which had just had a new firmware flash to fix a video problem from the previous week and was in the process of being flight tested again. I’ve never looked too closely at the mechanism before, but when it’s sitting on the undercarriage about to lift off, the rotors are tilted inwards slightly. Then, when the undercarriage comes up, the rotors tilt to a slight outwards angle for flight. I wonder what this transition does to it aerodynamically?
Anyway, after that we had a foam flying wing FPV and Vortex Quad, then the UMX SpaceWalker, F27 Stryker and Beast on a bike. I had a flight with my own RS352 before attempting the Stryker again, which was the one I crashed last week now repaired. He had stuck the nose back on and used fibreglass tape for the damage to the shoulder. We went though checking everything, including a range check, and I elected to fly on the high rates this time, knowing that I could flick the switch back down to low rates if needed. It flew beautifully, I even remarked part way through the flight that, “I think I’m flying Concorde”. Actually, it was rolling right quite badly and dipping into the ground, so I found a good throttle point to fly level and progressively added left and up trim until I was happy. About 6 left and 2 or 3 up did it. It’s not an easy plane to fly because you have to balance the aileron and elevator when turning. Too much aileron and the nose drops too much in the turn, the elevator won’t pick it up and you have to back off the aileron or screw into the ground. This might be a control harmonisation thing (needs more elevator?), but I’ve only flown it once so far. After checking the response to power off and glide, then going through some aerobatics as the confidence built up, we decided that landing with power was a good idea and brought it in after about 6 minutes. The landing was a nice flat glide, with little or no flare, as you expect from a fast aircraft like this, speed coming off nicely until it plopped down in the long grass in front of me. This is where it gets a bit weird, as I thought it had AS3X stabilisation as you could hear the servos chattering away, although the surfaces weren’t moving in any way I could see. The owner didn’t think it had stabilisation, so we looked on the box – it doesn’t. Now I’m worried because this might be what the problem was before. What’s causing the chattering noise if not the stabilisation? It can only be servo noise which suggests an electronic problem. Maybe I got lucky this time and the radio worked through the whole flight, but I’ll have to check it out to see if this is normal for a Stryker before flying it again.
I managed to get 4 flights in with my RS352, plus another one with the UMX SpaceWalker from last week. I think it is still suffering from radio problems as well, as I spiralled it into the ground again and bent the motor shaft a little bit. Determined to get to the bottom of this aircraft, I went up again and was very careful to fly without using any big control inputs. I just nudged it around the sky very carefully, or at least as carefully as I could now the wind had increased and the aircraft had trouble moving forwards against it. I was flying it like a quad at one point, with the right stick forward to penetrate and modulating the power. What I’m wondering is whether there is part of the flight envelope where a big rudder input causes the aircraft to suddenly flick in that direction, maybe the structure flexes as well, but then no recovery is possible? After all, it’s just a simple rudder elevator model with huge dihedral and comparatively little rudder movement. I need to try this out on a calm day and see if I can cause the problem deliberately. On the other hand, it could just be the radio. It did definitely fail last week, but not at all on the final flight today. It’s still a 30 gramme mystery.
We also had a new guy with an as yet unflown DJI Phantom 3, some guys were also flying two Phantom looking quads at the edge of the field near the stream, then a guy with another FPV quad arrived. Next came two Multiplex Easy Stars with FPV, the Hobby King Bixler which had been modified with removable wings and tail but had forgotten the radio and couldn’t fly, then finally a guy with his family and a FunCub arrived.
The title of this post comes from the flight of one of the Easy Stars, where he hand launched it, it did a big low right hand turn 180 degrees, flying 6 feet over our heads and then arcing into the ground behind us. If you look carefully in the picture above, it’s just over one of the trees in the middle.
OK, next week is a Bank Holiday so I need to get the AutoGyro flight ready. I’ve done nothing on it this week because of work.