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ACRO E-mail Archive Thread: [Acro] Re:


Thread: [Acro] Re:

Message: [Acro] Re:

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From: Klusmanp at

Date: Mon, 22 Apr 2002 22:43:15 UTC


  I had somebody explain it to me as the tip of the forward-moving wing is 
still flying while the aft-moving wing is completely stalled. Forward stick 
(nose down) leans the lift vector of the forward moving wing more forward. 
The aft moving wing is still stalled and does not change its lift (drag) 
vector. The net result is rotation speed increases.

It would be interesting to put some yarn tufts on the upper surface of a low 
wing airplane and observe the areas of the wing that are stalled during a 
spin. I'll bet NACA already did this years ago.

Paul Klusman
Pitts S-1S (hopefully in about another month or so)

In a message dated 4/20/02 6:46:06 AM EST, aboyd at writes:

<< 2) On p 116 (Advanced) Mike seem to have the curious opinion 
 that forward stick accelerates a spin solely because of rudder 
 blanking.  This is repeated on p 117, and on pages 111 and 112
 large diagrams explain rudder blanking and elevator position
 in upright and inverted spins.  But most pilots might agree that
 decreased radius of gyration (like a figure skater pulling her
 arms in when she's spinning) and drag (less AOA, less Cd) 
 reduction (like forward stick in a snap) are probably at least 
 as important factors as rudder blanking in accelerating a spin 
 with relaxed elevator. >>


© Dr. Günther Eichhorn
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