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06-04-2010 | 09:49 AM

#22

Iflyglow

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From: Clintonville, WI

RE: Engine Torque Problem

Quote:

ORIGINAL: LNEWQBAN

Thank you for the link to the videos, Iflyglow.

It seems to me that the right roll was produced by three simultaneous things:
1) Sudden power up (the last second increase in rpm can be seen in the video).
2) Quick full elevator up.
3) Right wing tip hooked under the tail of the other plane (view of which may have motivated the reaction of the pilot, who had blind frontal view). I can only imagine the confusion of the unfortunate pilot at that very moment. Left wing was free to lift, and it lifted hard as soon as its AOA was increased by elevator up.

Left roll was induced by 1, due to sudden engine torque.
Right yaw was produced by 1 and 2 combined, due to propeller being tilted backwards. This is called Gyroscopic Precession, and it can overpower the P-factor for big and heavy propellers.

http://www.faatest.com/books/FLT/Cha...opicAction.htm

The OP problem seems to be too much elevator too soon, combined with bad right landing gear, gyroscopic precession and a little of right rudder. The result was a right snap roll. Torque was helping him save the model.

I still do not totally agree on the sudden power up to go around, since he had allready hit the other guy with his prop which easily could have messed up the prop blades which would have given the sound of a power up. The crasgh was caused by collision with another plane and intanglement with the other plane. Its pretty clear that his left wing tip was caught under the other plane, and leveraged him to flip to the right.

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