I don't think the effect of airflow on the horizontal stabiliser has yet been mentioned.
I was taught that when the engine quits, reduced lift due to lowering the lever and low RPM causes descent and hence upward force on the rear stabiliser which causes a nose down attitude. Aft cyclic should be applied to counter this to maintain the autorotative angle of attack. Simply lowering the lever may not provide enough angle of attack if the RPM has fallen significantly. Sure, drag is reduced, but there must be an appreciable angle between the rotational airflow and the relative airflow. Pushing the cyclic forward reduces this vital difference in the two airflows.
Once the RPM is back in the green forward cyclic may be applied if there is time but that's gravy in the climb.
Forward cyclic with low rotor RPM is a recipe for disaster as this reduces the inflow angle required for autorotation.
My own experience suggests that tight turns are also effective at recovering RPM so maybe aft and sideways cyclic is indicated.
Any thoughts anyone?
Last edited by Gaseous; 24th May 2004 at 21:44.