Spin

A spin is a stable autorotation of a fully stalled aircraft about the vertical axis. One wing is deeper in stall than the other → asymmetry → continuous rotation.

Phases of a spin

1. Incipient spin (entry phase, 1–4 turns)

Transition from stall to developed spin.
Duration: about 2–4 seconds.
Yaw + roll + pitch all changing chaotically.
Recovery still easy.

2. Developed spin (developed, > 4 turns)

Stable autorotation: constant rotation rate, stable pitch.
Sink rate high: 3000–8000 fpm (type-dependent).
Spin direction clear (left or right spin).
Duration: until recovery or ground impact.

3. Spin recovery

With correct method recoverable within 1–2 turns.
Altitude loss during recovery: typically 500–1500 ft.

Spin onset

Prerequisites:

Stall (α > α_stall on both wings).
Yaw component (e.g. asymmetric stall, uncoordinated yaw, skidding turn).
High AoA maintained (yoke back).

Classic scenario: approach stall with simultaneous slip → one wing stalls first → autorotation.

Standard recovery — PARE

Per FAA-H-8083-3B Chapter 5 (applies to most GA aircraft without POH-specific procedure):

P — Power IDLE (throttle back).
A — Ailerons NEUTRAL (ailerons can worsen spin).
R — Rudder FULL OPPOSITE (against spin direction).
E — Elevator FORWARD (yoke forward, breaks stall).

When rotation stops: rudder neutral, pull out of steep nose-down to normal pitch.

POH governance

Important: some aircraft have specific spin recovery procedures in POH:

Cessna 172 (standard): PARE as above.
Diamond DA-40: spin-resistance certified, but not a full recovery trainer.
Aerobatic trainer (e.g. Cessna Aerobat, Citabria): explicit spin trainers.
Not certified for spins: STRICTLY FORBIDDEN — recovery may not be reliable.

Spin prevention — pilotage

Recognise prerequisites in advance:

Avoidance: do not enter stall + yaw.
On stall warning: immediate recovery (yoke forward).
In turns: coordinated turn (ball centred).
Low altitude: 1000 ft AGL absolute minimum for any stall/spin exercise.

Spin-resistant vs spin-recoverable

Certification per CS-23:

Spin-resistant: aircraft resists spin onset — even under extreme pilot input. Example: Cirrus SR22.
Spin-recoverable: spin can occur but recovery has been demonstrated. Example: Cessna 172.
Not certified for intentional spin: spin exercises forbidden. Example: Cirrus SR22.

Statistics

NTSB data: GA loss-of-control (LOC-I) accidents are the most frequent fatal accident category, many with stall-spin mechanism. Typical scenarios:

Base-to-final stall-spin: tight approach with uncoordinated controls → classic fatality.
Go-around with skid: too much rudder on go-around → low-altitude spin.

PPL training

Spins are not primarily in the PPL skill test (CS-FCL.235), but stall recovery demonstration is mandatory. Spin awareness and avoidance are extensively covered.

Some schools offer spin endorsement as add-on for aerobatic or spin-certified aircraft.