Stalls, spins & spiral dives
A wing stalls when it exceeds its critical angle of attack (about 17° for most aerofoils), not at a fixed speed. You can stall at any airspeed or attitude.
- Accelerated stall: in a steep turn the load factor raises the stall speed by √(load factor), so the wing stalls at a higher speed than the book 1 g figure.
A spin is an aggravated stall with yaw: one wing is more stalled than the other, so the aircraft autorotates. It passes through an incipient phase before becoming fully developed.
Spin recovery (PARE):
- Power: idle.
- Ailerons: neutral.
- Rudder: full opposite the spin.
- Elevator: forward to break the stall.
- Then level the wings and recover from the dive.
A spiral dive is not a stall. The wings are still flying, airspeed is high and increasing and load factor is building. Recover by reducing power, levelling the wings, then gently easing out of the dive.
Trap: treating a spiral like a spin, or just hauling back. In a spiral you level the wings first, then ease out; pulling early overspeeds and overstresses the airframe.
References
- TP 1102 (Flight Training Manual)