ID #1015

Can the slip/skid ball be used for spin recovery?

When IMC or disoriented, can the slip/skid ball be used to determine direction of spin and proper rudder necessary for recovery?


To quote Rich Stowell in Stall/Spin Awareness, Critical Flight Operations page 331, "Author and instructor William K. Kershner provides yet another classic demosatration of inherent limitations in the slip / skid ball. In the Third Edition of his bood, The Flight Instructor's Manual, Kershner describes installing additional inclinometers on the instrument panel in front of each seat of a Cessna 150 Aerobat and a Beech Sport [that is, on either side of the longitudinal axis--Nagorski] . Kershner notes that the two slip / skid balls would consistently end up in opposite corners of the inclinometers during spins. One ball would be off to the left side; the other ball would be off to the right side. This was observed in both airplanes. Hence, we absolutely cannot rely on the ball for spin direction information"


Stowell also emphasizes this point in the handout "Twelve Stall/Spin Myths Exposed":

Myth #6: During spins, the slip / skid indicator shows spin direction.

Reality: The slip / skid ball is totally unreliable when spinning.




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