[Ref. The Pilot’s Manual PM2 Ground School Page 86 – 89]
Spin – stalled plane enters the autorotation following a spiral axis
Phases of spin:
- Stall
- Incipient stage of spin
- Fully developed spin
- Recovery spin
To spin –
- BOTH wings stalled
- the dropping wing is more deeply stalled than the other
- greater drag on dropping wing
- result further yaw and further roll
- autoroation develops
Symptoms of Spin:
- nose (attitude) is upward pitching
- high rate of descent – altitude loss rapidly
- Airspeed low and fluctating – due wings stalled
Spin Recovery
- Power off
- full opposite rudder – to oppose the yaw
Extended Reading –
Autorotation
- auto roll
- more deeply stalled wing generates less lift which tends to be dropping
- while the upper wing travels faster and thus generates more lift.
- auto yaw
- more deeply stalled wing generates more drag – tends to yaw the nose in same direction as the roll
The above combination (auto roll + auto yaw) makes the rolling-yawing even self-sustaining, or automatic.
This natural tendency is named as autorotation – which is the basis of the spin.
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