Autogyro Days

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I wasn’t really planning on flying this week, but the forecast was for good weather with a 10mph breeze and I had finished the modifications to the autogyro’s blades. The shims are a little bit more than the only successful flight so far, so about 1mm where they were 0.8mm before. I was determined to test the autogyro again, but things didn’t work out exactly as planned.

I was the first one there this morning, closely followed by a UMX Super Cub with ailerons, flaps and AS3X stabilisation. This was my first flight of the morning, as I flew it for the owner in the very blustery conditions. It flew beautifully, with me pointing out from the launch that I wasn’t actually doing anything. It knew how to fly all on its own, which is impressive for something that’s not much over 30g in what was by now really turbulent windy conditions. After that another old friend who I haven’t seen in months turned up with his Multiplex Xeno flying wing. We had another guy who test flew his first aircraft the day before and showed us the evidence on his phone. It was a low wing stubby sort of a plane, which looked a bit like a lazy bee, but surely wasn’t suitable for beginners? We saw it roll along the ground, roll and yaw left, clip the left wing on the ground and turn over. It looked OK, but none of us fancied flying it. He said he’d be back next week, so that should be interesting. Other than that, we had a professional drone pilot who wanted to keep his flying hours up on a Mavic and a couple of kids towards the end of the morning who looked like they didn’t know how to fly a DJI Phantom.

OK, so after the Cub, I flew the Atom Autogyro. To cut a long story short, it crashed 26 seconds after a really successful hand launch. I have the video of the launch, plus my friend also filmed it on his phone. On my video, which was using the wide-angle runcam, you can just see the start of the crash, but it’s too far to really see and then the actual plummet to earth and crash is out of the frame. What I think happened was that one of the main rotor blades struck the prop, shearing the end off of the rotor blade and stopping the main rotor from spinning. From my point of view, it was a perfect launch, it drifted left a bit, gained height well, I turned right, went across in front of myself with the wind blowing in my face, got to the right hand edge of the box I was flying, went to turn right again to come back and something flew up from the rotor disk. I assumed a blade had snapped, but was then aware that the rotors had all folded themselves up and were no longer spinning. At this point I put the thrust to zero and realised that there was nothing I could do as the aerodynamic control is all through the rotor head. No spinning head, no control. The fuselage was heading towards the earth at a 45 degree angle and there’s no lifting surface, so it’s like when the wing bands break and the fuselage spears into the ground on its own like a javelin. Admittedly, I still had rudder and throttle control, but I can’t see that using the rudder to roll to a higher drag orientation would do less damage. I figured that 45 degrees into the ground with the nose and wheels taking the impact is the best option.

On inspection of the damage, it was evident that 11cm of the tip of one of the blades was missing. It had landed a long way from the main wreckage, so this was obviously what I had seen flying up off the aircraft in the air. We thought that the tail was the likely source of the impact, but there is a gauge out of the spruce leading edge of the blade and score marks which suggest a more violent impact.

 

 

The vertical fins are also fairly intact, although the impact with the ground has broken both of the spruce tail spars. The wheels have sheared off most of the front section, along with the motor and firewall. That will need replacing and strengthening with ply. Pete the pilot has also been decapitated, but he’s easy to stick back together. I might even give him some better goggles while I’m at it. So, basically, it should fly again, but the damage is quite extensive.

 

After the autogyro crash, I had three flights with the RS352. One of my four batteries has definitely had it, so I’m going to have to retire it after just under two years of use. Although I’ve flown the RS352 in some really bad weather conditions, it was surprisingly bumpy in the air today. On the first flight I actually switched out my flaps and flew without the extra camber, going a lot faster, but with down trim. My flying was really ragged today, or maybe it was just the conditions? I suspect the wind may have played a part in the autogyro crash, because, even with my usual aerobatic aircraft, it was a real handful today. It might be something to do with being right on the edge of ex-hurricane Ophelia, which we’re going to get the tail end of tonight.

Oh, well, I’ve got some building to do now.

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That’s the Xeno on the left (very small) and a bird on the right.

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