Thomas Coupling -
I wrote 'The last time I renewed by Inst. rating in UK We did TRUE TR failure in the hover'
I used 'true' in preference to 'real' as I thought the latter unsuitable.
I can see your point, we can only simulate having no TR thrust but cannot disconnect the TR so we have to get as close as possible
by using full right pedal.
Isn't this actually a very accurate simulation though? The TR has to be capable of making thrust in both left and right directions, one of the main reasons for that requirement being that friction effect in autorotation (nose yaws left) must be balanced by TR thrust in the opposite direction to powered flight.
(The neutral position for TR thrust on the ground in an R22 is with the right pedal a good deal forward, not with the pedals level with each other. The TR is rigged to give more control range to the left for powered flight)
Somewhere inbetween full left pedal and full right pedal there is a completely neutral TR pitch setting which is the same as having no TR thrust at all. If you use full right pedal you are actually PAST the zero TR thrust to the right value and into the (narrower)thrust to the left range. That must be ADDING to the speed of right yaw that would result from having no TR thrust due to a true (true making the distinction between a complete loss of TR thrust and other problems such as control failure or jamming) TR failure.
So it seems to me that full right pedal in the hover is a very realistic way of simulating a complete loss of TR thrust in the hover. It gives a greater yaw rate than a complete loss of TR thrust would do in the same profile.
I agree that it would be good to hear from any low hours pilots reading on the sideline, I think that the forum would benefit if more of that were to happen.
Moving on, The control failure in the hover (UK) that I saw was caused by a TR swashplate bearing siezure. The swashplate then wanted to rotate with the TR driveshaft which broke the horn control connection and left the TR in a fixed pitch state. The Instructor got it down fine although it was yawing slowly, I cant remember in which direction but guess that it must have been to the left as the lever was lowered to land.
It is important to note that this was a machine left outside in all UK weathers and had done around 1200 hrs. The bearing is lifed for 2000 hrs but leaving it to be ravaged by those conditions can do it no good at all.