Originally Posted by
SASless
Now I never claimed to be the sharpest knife in the drawer but I always wondered about this accelerate forward to escape from IVRS/VRS as I was led to believe it was caused by descending into. a descending column of air caused usually be being slightly downwind and that pulling power only added to that problem.
Last time I checked most helicopters (smaller lighter aircraft as compared to the strongly powered behemoths that according to some can use power alone to escape....lowering the nose to accelerate gives a negative effective for ROC and demands more power which would add to the downward velocity of the air column.
The goal is to get out of the downward flow of air....and it seems intuitively obvious that the shortest direction to do that would be to either side rather than forward as in my mind the shape of that downward moving column of air is not going to be circular but rather more of an elliptical shape (longer fore and aft and narrower side to side).
Also...a turn into wind rather than extending your down wind approach with a higher ground speed close to the ground has undone many a helicopter and pilot.
I suppose the nice folks at the CAA don't care much for teaching Tail Rotor Emergency procedures using rotor rpm and collective when the pedals are not working as advertised either.
Does it matter what labels are affixed to the situation or recovery techniques or can we just talk about the effect of flight controls and applications of power, etc and not get hung up on the labels?
I can almost hear the near Gregorian Chant of Vulchard, Vulchard, .....GO!
The thing about pushing forward to get out of VRS, is that we're always practicing it with a vertical fall from an OGE hover, where pushing forward does move you clear.
In reality though, it'd probably be more like that video they show at the Robby Course where the R44 is on a downwind approach to a rooftop, gets into VRS, hits hard, slides across the roof, then gets dynamic rollover and falls to his death.
He had forward movement, so probably didn't realize he was in it until too low, but thing is, with his already forward momentum, would pushing the nose forward even get him out of VRS?
Seems no one ever talks about this when it comes to the "traditional" recovery technique.