4.spin-recovery. Spin Recovery
A spin is an aggravated stall that results in autorotation — the airplane follows a downward corkscrew path around a vertical axis while one wing remains more deeply stalled than the other. Recovery from a spin requires deliberate, correctly sequenced control inputs. Random or simultaneous control movements can prolong the spin or transition it into a different mode (flat or accelerated) that is harder to recover.
The FAA-recommended generic spin recovery procedure, applicable when the airplane manufacturer does not specify a different technique, is summarized by the mnemonic PARE:
- P — Power to idle. Reducing power eliminates the propeller's gyroscopic and slipstream effects, which on most airplanes tend to flatten the spin and aggravate the yaw rate.
- A — Ailerons neutral. Aileron deflection in a spin can drive the wings to different angles of attack, possibly accelerating the spin or causing it to flatten. Neutralizing them removes that variable.
- R — Rudder full opposite to the direction of rotation. Determine spin direction by reference to the turn coordinator (ball position is unreliable in a spin) or outside visual cues. Full opposite rudder breaks the yaw that sustains autorotation.
- E — Elevator briskly forward through approximately neutral, far enough to break the stall. The exact amount varies with airplane type; some airplanes require a definite forward push, while others need only a relaxation of back pressure.
After the rotation stops, neutralize the rudder to prevent yawing into a spin in the opposite direction, then smoothly recover from the resulting nose-low dive. Pull out gradually — abrupt elevator inputs can produce an accelerated (secondary) stall or exceed the design load factor. Apply power as the nose approaches the horizon and return to coordinated flight.
Always consult and follow the airplane's POH/AFM spin recovery procedure first. Manufacturer techniques take precedence over the generic PARE procedure because spin characteristics vary by design (CG location, mass distribution, tail geometry, and wing planform).
Phases of a Spin
- Entry — the pilot (intentionally or unintentionally) provides the inputs necessary to cause autorotation: a stalled wing combined with yaw.
- Incipient phase — the airplane is yawing and rolling toward the spin attitude; lasts about 4 to 6 seconds, or roughly the first 2 turns. Recovery here is generally rapid.
- Developed phase — airspeed, vertical descent rate, and rotation rate stabilize. Aerodynamic forces are in equilibrium with inertial forces.
- Recovery — the wing is unstalled and rotation stops. Altitude loss continues during the dive recovery; total altitude loss in a one-turn spin in a typical training airplane is commonly 1,000 ft or more.
Spin Modes
- Upright (erect) spin — positive angle of attack, positive G; the most common type encountered in training.
- Inverted spin — negative angle of attack, negative G.
- Flat spin — pitch attitude near level with very high rotation rate; aggravated by aft CG and improper power/aileron use. May be unrecoverable.
- Accelerated spin — increasing rotation rate, often caused by in-spin aileron or power.
Loading and Placards
Most normal-category airplanes are placarded against intentional spins and are not certificated for spin entry. Only airplanes certificated in the utility or acrobatic category (per 14 CFR Part 23), and loaded within the prescribed weight and CG envelope for spins, may be intentionally spun. Aft CG dramatically degrades spin recovery characteristics — a lightly loaded airplane within the normal CG range may still be outside the spin-approved envelope.
Before any intentional spin training, verify:
- The airplane is approved for spins (POH limitations and cockpit placards).
- Weight and CG are within spin-approved limits.
- Baggage compartment is empty or secured per limitations.
- Sufficient altitude for recovery — most training spins begin no lower than 1,500 ft AGL above the planned recovery altitude, with recovery completed no lower than 1,500 ft AGL.
- Pre-spin clearing turns are completed.
Common Errors
- Failing to identify spin direction correctly, then applying rudder the wrong way.
- Applying aileron into or out of the spin, changing the spin mode.
- Holding the elevator full aft, keeping the wing stalled and the spin developed.
- Pulling out of the recovery dive too aggressively, causing a secondary stall or overstress.
- Failing to retard power, allowing propeller effects to flatten the spin.
Spin awareness — recognizing the conditions that lead to inadvertent spins (uncoordinated flight at low airspeed, particularly the cross-controlled stall in the base-to-final turn) — is far more valuable for the typical pilot than recovery technique alone. Avoid the entry conditions and a recovery is never needed.