Chair flying / Steep Spiral
Steep Spiral
A gliding descent of at least three constant-radius turns around a ground reference, correcting bank for wind to hold the radius — practice for a power-off descent to a landing area. A commercial maneuver.
Pre-Maneuver Checklist (CRAAC)
- Clearing turns — two 90° turns or one 180° turn; look for traffic
- Reference point — select a visual reference and set the heading bug
- Altitude — high enough to complete the maneuver at or above 1,500 ft AGLACS minimums: slow flight and stall recovery complete ≥1,500 ft AGL; ground reference maneuvers enter at 600–1,000 ft AGL.
- Airspeed — at or below Va (105 @ 2,325 lb / 90 @ 1,900 lb kt)
- Configuration — fuel pump ON, lights ON, mixture RICH, flaps as needed
Setup
- 85 kt (approx. 2,100 RPM)
- Clean configuration flow
- Choose a visual reference point
Execution
- Reduce throttle to idle
- Track three constant-radius circles around the reference pointAdjust bank for wind to keep the radius constant — steepest downwind, shallowest upwind — but do not exceed 60° of bank.
- Hold a constant airspeed; clear the engine once every 360° turnClearing the engine (briefly advancing the throttle each turn) keeps it warm and prevents plug fouling during the long idle descent.
Recovery
- Recover by rolling out on the specified heading or visual reference
ACS tolerances
- Airspeed constant, ±10 kt
- Constant radius, bank not to exceed 60°
Common errors
- Inconsistent radius from poor wind correction
- Letting airspeed drift during the descent
- Forgetting to clear the engine each turn