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Old July 6th 18, 10:08 PM posted to rec.aviation.soaring
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Default Accelerated spin in unexpected direction at low altitude











n Friday, July 6, 2018 at 3:14:51 PM UTC-4, Steve Koerner wrote:
It is confusing when the top wing is coming down instead of the bottom wing, for sure, but the airplane is spinning to the direction of the rudder. To recover, opposite rudder and forward stick is needed, just like the "normal" spin.
Dan
Normally you think of a spin associated with turning flight where there is an inside wing that is going slower than the outside wing and thus already at a higher AOA than the outside wing. The discussion about flipping into a spin to the outside seems very weird until you start thinking about a turn at very high bank angle.

Consider a turn at 90 deg bank angle. In that case there no longer is an inside wing going slower than the other. Both wings are on equal footing with respect to their vulnerability to stall. In a very steep turn, it's easy to see that the top wing could well stall first if there was a bit of yawing action introduced or if the air had the right sort of irregularity to it. Near the ground, horizontal wind shear is the commonplace and could easily provide the irregularity that would be the impetus for a "backwards" spin. Clearly, depending on the degree of shear that's going on, the bank angle could be well less than 90 degrees and still get the backwards spin induced.