Puchaz Spinning thread that might be of interest in light of the recent accident.

In article ,
jhandl wrote:
On Thu, 05 Feb 2004 10:22:11 -0500, Todd Pattist
wrote:

Jim wrote:
I should not have gone farther than just the
observation that the inside wing in a stable descending turn is
going down while the outside wing is going up ( and the opposite
situation in an ascending turn).

This is incorrect. Both wings are going down (and both are
going forward). They both go down at the same rate, they go
forward at different rates (inner wing slower). If you think
about it, that means that the inner wing has a higher AOA.

I was just reading the Gider Pilot Manual by Ken Steward, pages 68 &
69. There he talks about the larger angle of attack difference in
shallow turns than in steep turns, because of the larger difference in
the circumference described by both wingtips, and concludes that steep
turns are safer than shallow turns.

I believe Steward left out an important factor, intentionally or not.
Even if the the distance between the inner and the outer circles is
larger in shallow turns, they also are much wider, and that has a
large impact in the AOA difference. Otherwise, the shalowest turn
would have the largest AOA difference, which is clearly not true.

So far this thread talked about one bank angle. Would anybody care to
compute the AOA delta for the whole range of bank angles? I guess it
would be given as a function of the wing span...

I'm figuring bank angle, airspeed, and wingspan are the three
factors. What would be really interesting is comparing the results
against the airspeeds given in the simple bank angle
tables for G loading found in many books, POH's and manuals.

If one flies the airspeeds for the bank angles shown on these
charts, for each glider (pick some popular ones), what is
the bank angle that causes the highest ratio of
airspeed between outer wingtip and inner wingtip?

Perhaps Bob Hanson at St. Olaf can be convinced to code this up