FAA Commercial Pilot Airplane (CAX)Aerodynamics and PerformanceMedium
During a fully developed spin, which wing experiences a higher angle of attack, and what effect does this have on the spin?
- AThe descending wing has a lower angle of attack, causing the spin to recover naturally
- BThe rising (outside) wing has a higher angle of attack, slowing the spin
- CBoth wings have identical angles of attack, resulting in a stable spiral
- DThe descending (inside) wing has a higher angle of attack, sustaining the spin through autorotation
Show answer & explanationAnswer & explanation
Correct answer: D. The descending (inside) wing has a higher angle of attack, sustaining the spin through autorotation
In a spin, the descending (inside) wing has a higher angle of attack and remains more deeply stalled, producing less lift and more drag than the rising wing. This asymmetric lift and drag condition, called autorotation, sustains the spin until corrective control inputs are applied.
Why the other options are wrong
- A. A spin does not recover on its own without proper control inputs.
- B. The rising wing actually has a lower angle of attack and produces more lift, not less.
- C. The wings do not have identical angles of attack during a spin; the asymmetry is what sustains it.
Spin Autorotation
Autorotation is the self-sustaining rolling and yawing motion in a spin caused by the descending wing having a higher angle of attack and being more deeply stalled than the rising wing.
- Descending wing: higher AOA, more stalled, less lift, more drag
- Rising wing: lower AOA, less stalled, more lift, less drag
- Asymmetric lift/drag drives continued rotation
- Proper spin recovery breaks the stall on the descending wing
Memory trick: Down wing stalls deep, keeps the spin's beat!