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Old 27th Sep 2016, 06:57
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megan
 
Join Date: Mar 2005
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Calling Nick Lappos - Blade Stall

We have a gentleman (AnFI) who's posted the following on another thread,
Interesting youtube is littered with these 'high speed stall' accidents

The point about coning angle is really interesting. There is effectively a conning angle at which a disk is in effect stalled, regardless of RRPM.

RRPM 'cancels out of the maths' when you look for stall.
and
cone is proportional to the ratio of Lift (L) to Centripetal Force (Cf)
both L and Cf are proportional to RRPM^2

take a helicopter in the hover at low load and low RRPM (such that it is very close to stall AoA)
measure the cone
if load is increased the RRPM has to be increased to increase Lift
the AoA remains just short of stall and the coning angle is unchanged.
that coning angle is the coning angle just short of stall
Comment specifically on his "There is effectively a conning angle at which a disk is in effect stalled, regardless of RRPM" would be appreciated.

I've been invited by the poster to write my own technical paper, but thought I'd gain expert opinion first. We can discuss consultation fees by PM. Glad to see up, about and engaged.
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