Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)

[jrc <jrccea@bellsouth.net>]

----- Original Message ----- 
From: "Erik Boehm" <erikboehm07@yahoo.com>
To: "DML" <dinosaur@usc.edu>; <david.marjanovic@gmx.at>
Sent: Monday, September 29, 2008 10:15 AM
Subject: Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)


> When it comes to rotary wings, they don't have a conventional stall speed, 
> rather the velocity component of the air flowing perpendicular to the 
> rotor disk must be above a certain rate for a given blade pitch to keep 
> the blades rotating.
> For a given pitch the blades must be at a certain rpm, or the blades 
> stall.

Which is the reason that the retreating blade on a helicopter or autogyro is 
flown at a higher angle of attack than the advancing blade.  The upper speed 
limit for helicopters under power is set by retreating blade stall.
JimC