Quote:
Originally Posted by svandamme
If I understand it correctly, this Low G and Mast bumping is the Helicopter equivalent of Aerodynamic Stall and departing the plane in a fixed wing ? With one major difference, you can recover after departing a fixed wing, but mast bumping is kinda way worse and usually more final.
Does that at all make sense?
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That statement does not make sense, not sure what you're trying to say.
Mast bumping and (rotor) stall is unlike a stall in a fixed wing, rotor stall is not recoverable. Stall in a fixed wing aircraft is almost always recoverable.
Low G along with mast bumping are completely separate issues from rotor stall. Mast bumping can result from low G. The Robinson in the video either had a structural failure, or, more likely suffered from a low G condition. When a two bladed, underslung rotor system becomes unloaded (in a low G situation or possible heavy turbulence), the rotor system may not respond to control system (cyclic) input in the way the pilot would expect.
An aft cyclic input may result in the blades contacting the tail boom. Or, with the main rotor unloaded, the rotor bump stops can make contact with the mast causing separation of the main rotor system (not what happened in the video).
It is also possible they were practicing low rotor RPM recovery and let it go too far (unlikely but possible). The stalled rotor then may have contacted the tail boom. I doubt this was the case.
Of my flying time, about 3000 hours of it is in two bladed Bell products (206L) with some Robinson time as well. This stuff is fundamental. All this is drilled into new Robinson instructors and I'd heard there was an instructor and student on board.