Predator or Predator X?

If it's the origional Predator, try tightening up the covering a bit.

If that doesn't help, just don't fly that fast. I've twice seen Predators "flap" when the plastic spar manages to twist and buckle. In both cases the pilot was able to cut the throttle and land safely, but you should be aware that the spar on the Predator can buckle. In both cases, the Predator was really screaming along, easily going faster and turning harder than the design intended.

One of the two I saw was mine, btw. I am pretty sure that I had the RX and servo cutouts too close to the spar and that contributed to the problem. The OS .32F had on the nose was a factor, too, I imagine.