Originally Posted by
Thomas coupling
That world record always amazes me. No-one has even come close since have they? If the ASI was off the clock how did he auto in IMC safely? I understand he was iced up on the windscreen for up to 6 minutes duration???
Fantastic feat of aviation. 1972 I believe?
Please enlighten me. Getting up, yes. But getting down: I seem to be missing what the big problem is?
I don't know the details, but the previous poster seem to simply have said that (presumably and in-line with the topic of this thread) the IAS due to VNE limitations at that ALT would have been so low that it didn't register on the ASI. It was not said that the ASI was u/s.
Either way, in an autorotation, what do you need the ASI for?? You can safely autorotate at any speed between a little backward, and power-off forward VNE. In fact, the lower the speed, the easier and more stable the auto is
. Forward speed only becomes useful a few seconds before the landing, so that you can flare and arrest your rate of decent at touch-down.
So enter autorotation, keep the ship level, set for low or zero speed, and control RRPM with collective. In any case, stay below VNE, which as other posters have pointed out, would announce itself with vibrations from the onset of RBS. As mentioned above, the sweet spot around zero IAS should easily identifiable by its stable ride.
I'd also venture to say that all VNE and RBS-related issues here are linked to high AoA (needed of powered forward flight to push speed): Conversely, in an auto where your AoA is almost zero, VNE limitations should be much less critical.
I would be more concerned if he didn't have an AH (seeing that at 42,000 ft you are deemed to be in IMC, plus he had his windows iced up). Not sure how those work in a Lama, but even if electric suction pump driven, he should have had battery power for the 20 to 30 min he was descending.
Having said this, I wasn't up there at 42,000 ft. It must have been scary in the best of circumstances. I am afraid of heights, that's why I fly chopper.