Saturday, December 6, 2008

Heli 3D: Piro Flip

I hope the reader is comfortable with controlled pirouette already before attempting the tips in this article, if not, do check out the previous entry on controlled pirouette.

Piroflip can be broken down to the following 3 steps
- Controlled pirouette
- Time the flip
- Flip

I'd start with the heli in upright pirouette and wait for tail-in, then give forward elevator to flip the heli. As the heli is constantly pirouetting, aileron input will also have to be given during the forward flip. This will speedup the transition of the heli to inverted in one revolution (one full pirouette).

We want to be able to transit the heli from tail-in upright to nose-in inverted in one revolution. Using only elevator input will be too slow and may take more than one pirouette to transit.

While the heli is inverted pirouetting, i'd wait for tail-in again, then give backward elevator and aileron input to transit the heli to upright in one revolution.

Ive uploaded a video which shows transition of a stationary heli to inverted and vice verse in one pirouette (mode 1).

After successfully transiting the heli in one revolution, the heli may want to drift around, just rely on your controlled pirouette skill to flatten the heli.

And heres another video which shows sticks movement of full piroflip (mode 1).

Too much drifting around?

Somehow, faster piro rate (at a rate controller to the pilot) helps in making PiroFlip easier to perform.

And try to have more piro per flip. I'd do at least 2 piro before flipping. 2 piro would normally allow enough time for me to flatten or re-position the heli.

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