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Old 28th Nov 2017, 19:25
  #109 (permalink)  
FH1100 Pilot
 
Join Date: Nov 2006
Location: Pensacola, Florida
Posts: 669
I guess I'm what they call "old school." Look, I learned to fly in a Bell 47 powered by a Franklin engine. In the summer. We spent a lot of time at WOT - literally wide-open throttle. You did NOT allow your engine/rotor rpm to droop on approach. Nobody taught us the modern term of "over-pitching." I guess that came with the Robbies.

By the same token, we learned quickly not to go into really tight or "hover-hole" LZ's where you might not be able to get back out even if you managed to not crash going in.

The thing about "SWP" (as we knew it) was the "disconnect" between the collective and the rate of descent. If you pulled up a bit and the helicopter went down faster, you were re-ingesting your own rotor vortices. Without that bit of evidence, you weren't in SWP. You still might not have enough power to stop at the bottom (if you couldn't get it into ground cushion before the skids hit), but that was your own screw-up, not that of the aircraft.

(Why any self-respecting pilot would continue to pull collective and bleed the rotor rpm down is beyond me. Rotor rpm is life. If you sacrifice it, it's your own damn fault.)

Same thing in governed, turbine helicopters. If moving the collective still modulates the rate of descent, then you're *not* in the FAA's version of SWP.

If you are at a power limit and the helicopter still keeps going down, then if you have the altitude you better get the hell out of there because something bad is about to happen; it's not going to get better. It doesn't matter at this point whether your vortices are above or below the rotor disk - you're about to crash.

Finally, I have never, ever heard of "SWP" being applied to a condition of flight when you're above ETL. If you come in fast, above ETL, and you don't for some reason have enough power to stop at the bottom, it's not SWP. It's you being a dumbass.
FH1100 Pilot is offline