Originally Posted by
Fly Aiprt
Grog,
The rudder is the primary control to stop a spin, and the elevator position must be so that most of the rudder area is subject to the slipstream.
Yes, to a point. If you watch the video carefully you will see that at no point does the PIC apply full opposite rudder and hold it. In fact the rudder changes places so much it is hard to understand what he was trying to accomplish, but for all the discussion about pro-spin and anti-spin aileron inputs it is a fact that without appropriate opposite yaw provided by the rudder autorotation will not stop. In actual fact this incident is somewhat reminiscent of my own experiences detailed elsewhere on PPRuNe. For whatever reasons the pilot did not apply opposite yaw for any sustained period of time and the autorotation continued as a result until FIT.
[QUOTE]The elevator nose up or nose down to recover from a spin depends on the configuration of the tail. Some aircraft (most Pitts for instance) require full nose up elevator to quickly stop spinning[QUOTE].
I have more than 1300 hours in Pitts S2A, S2B, S1S, S1T and S2S airplanes as well as as ton in similar higher-powered types. If you follow the direction "full nose up elevator to quickly stop spinning" you are going to be in for a long ride. The airplane will quickly mush into a deep stall, the autorotation will be sluggish but sustained, and I am guessing (because I have never tried) that you will not have enough rudder authority to overcome the deep stall the non-flying wing will be in. Normally once you have the aircraft autorotating you unload the airfoil as much as possible to increase rotational velocity and decrease drag. The airplane has enough rudder authority to keep it rotating even with elevator pretty much at neutral or just slightly nose-up. (Aside- if you want to go flat you bring in the power and then actually stuff in nose-down elevator to accelerate the spin if that's your desire for the day's entertainment...) In a normal spin, when you want to stop on a specific heading you release the loaded wings with roughly neutral elevator and kick opposite rudder. As the rotation slows you punch forward stick to fully unload the airfoil to 0G and use ailerons to fine-tune the rotation until you are on-heading and are pointed vertically straight down.
I have exactly 0 hours in any Yak so what I just wrote is not applicable here, other than as it applies to all aircraft types. In any case based on the video evidence it appears that the pilot either did not or could not apply proper anti-spin rudder for a sustained period of time to effectively stop the autorotation. I don't know when Polish authorities release accident reports but this is one I would be interested in seeing someday, especially to see if control continuity was present.
Warm regards,
dce