Today I finally got the glitches sorted out with the electric Edge 540R (I bought a 2.4GHz radio!), and put it through its paces properly for the first time. The first flight was great but the second got truly interesting.
I took off as normal, pulling into a vertical climb then a quarter loop and half roll at the top. The nose pitched quickly down. “Odd” I thought, “it can’t be a glitch with the new radio”. It was very windy aloft today so I trimmed it out again and flew on. A few minutes later the ailerons got sluggish and then I noticed a massive flutter in both, then no control in roll at all. Not good! I then noticed I had virtually no elevator control either and the model starting descending quickly. In the strong wind it drifted to the far end of the field.
Now, I’m either the greatest model pilot in the world or I got lucky! Somehow I managed to turn the nose into wind and keep the wings level using just the rudder the, just before I hit the long grass, I blipped the throttle long enough to level it out and slow it down. The model settled lightly in the grass with absolutely no damage at all.
Back on the ground the cause of the loss of control was easily apparent…
I had built this model (and its sister) exactly to the manufacturer’s instructions. The PCB board control horns were to be epoxied into the pre-cut slots. I had done this using 5 minute epoxy and tested each to make sure it was secure. Sadly, in flight these horns had failed all at the same time. The ailerons gave up completely and the elevator fortunately held on to give me just enough control to save the model (pulling out easily on the ground).
So, the moral of the story…
Don’t trust those instructions. PCB epoxied into hardwood slots simply isn’t enough to hold the force generated by full 3D control throws on a model like this. Personally, I’ll be replacing them with proper threaded rod control horns like I have used previously on my 25% scale models.