CPL Checkride Guide
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. It is practice for a power-off descent to a landing area. A commercial maneuver.

Guided rehearsal is PremiumACS V.B: Steep Spiral (ASEL, ASES)

Pre-Maneuver Checklist (CRAAC)

  1. Clearing turns: two 90° turns or one 180° turn; look for traffic
  2. Reference point: select a visual reference and set the heading bug
  3. Altitude: the task's entry altitude; ground reference 600–1,000 ft AGL, slow flight and stalls finish at or above 1,500 ft AGL
    Ground reference maneuvers enter at 600–1,000 ft AGL and hold altitude ±100 ft. Slow flight and stalls (and the commercial chandelles, lazy eights, and steep spiral) finish no lower than 1,500 ft AGL. Eights on pylons fly at pivotal altitude.
  4. Airspeed: at or below Va (105 @ 2,325 lb / 90 @ 1,900 lb kt)
  5. Configuration: fuel pump ON, lights ON, mixture RICH, flaps as needed

Setup

  1. 85 kt (approx. 2,100 RPM)
  2. Clean configuration flow
  3. Choose a visual reference point

Execution

  1. Reduce throttle to idle
  2. Track three constant-radius circles around the reference point
    Adjust bank for wind to keep the radius constant, steepest downwind and shallowest upwind, but do not exceed 60° of bank.
  3. Hold a constant airspeed; clear the engine once every 360° turn
    Clearing the engine (briefly advancing the throttle each turn) keeps it warm and prevents plug fouling during the long idle descent.

Recovery

  1. 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