Originally Posted by
Chock Puller
Next thing you know 212Man shall attempt to convince us it was all done on purpose and not merely because the AFCS kicked off.
Helicopters tend to accelerate rather quickly when pointing straight down like something akin to dropping a set of streamlined car keys.
Ever peg the VSI?
Drat - rumbled!
Yes, they do go downhill very quickly with even relatively modest pitch angles. I once hosted the senior design engineer for EGPWS from Honeywell, and we took him on a flight in the S-92. One purpose was to show how obstacle warnings could be a nuisance in a high density environment (lots of NUIs) but we also discussed the Mode 1 alerts and the (then) research into improving offshore modes. The Blackpool AS365 accident was still quite fresh in our minds and I tried to explain how quickly things could escalate. But, words can never replace experience so we carried out a series of dives from about 80 kts, with 5 degrees incremental increases in negative pitch. By 25 degrees he really got the message - I think we were hitting 5,000 ft/min in around 6 seconds!