Unrecoverable Vortex Ring State
After reading the discussions on the Blackhawk accident threads, could it be possible to get into an unrecoverable VRS? Say a helo is in a full blown VRS with a huge ROD of 4000+ fpm. Could it be possible that:
1. The rotor is completely stalled and so cyclic pitch changes will have no effect on disc attitude, or
2. With such a huge ROD, even with the collective on the floor, the ROD airflow is large enough to give a resultant relative airflow and angle of attack that exceeds the stalling angle on the rotor blade?
I have been in many doozies in the training environment and have always effected the recovery before the ROD exceeded 3000 fpm, but I always presumed some parts of the rotor disc were still doing something right. Any ideas or test data to prove or disprove my theory?