Steep Spiral
The steep spiral is a performance maneuver that rapidly dissipates substantial amounts of altitude while remaining over a selected spot.
Similar to turns around a point, the pilot maintains a constant radius around a surface-based reference point while rapidly descending. At least three 360° turns are completed in the maneuver, terminating no lower than 1,500 AGL.
To perform a steep spiral, the throttle is closed to idle and carburetor heat is applied (if equipped). The aircraft is trimmed for gliding speed.
After glide speed is established, pitch is lowered and the wings are banked no greater than 60º. A constant-radius turn is accomplished by correcting for wind drift, with steeper angles as the airplane turns into a headwind and shallower angles when the airplane has a tailwind.
Maintaining a constant airspeed throughout a steep spiral is an important skill, since airspeed tends to fluctuate as the bank angle changes.
After three turns, the pilot should roll out toward a definite object or on a specific heading, recovering to a wings-level glide with no change in airspeed, followed by normal cruise flight.
Airman Certification Standards
- Select an altitude sufficient to continue through a series of at least three 360° turns.
- Establish and maintain a steep spiral, not to exceed 60º angle of bank, to maintain a constant radius about a suitable ground reference point.
- Apply wind drift correction to track a constant radius circle around selected reference point with bank not to exceed 60º at steepest point in turn.
- Divide attention between airplane control and ground track, while maintaining coordinated flight.
- Maintain the specified airspeed, ±10 knots, rolls out toward object or specified heading, ±10º.