A commercial pilot applicant is demonstrating a steep spiral. According to the Commercial Pilot ACS, which of the following is a required performance element of this maneuver?
- AMaintain a constant airspeed at Vno while descending at idle power in a steep bank
- BMaintain a constant radius around a selected point while completing a minimum of three 360° turns and rolling out on a specified heading within ±10°
- CComplete the maneuver using a single continuous 360° turn without clearing the engine
- DMaintain a constant bank angle of exactly 45° throughout the entire descent regardless of wind conditions
Show answer & explanationAnswer & explanation
Correct answer: B. Maintain a constant radius around a selected point while completing a minimum of three 360° turns and rolling out on a specified heading within ±10°
The Commercial Pilot ACS requires the steep spiral to be performed with a constant radius around a selected point on the ground, completing a minimum of three 360° turns, clearing the engine periodically, maintaining airspeed within ±10 knots, and rolling out on a heading within ±10° of a specified heading, without exceeding a bank angle of 60°.
Why the other options are wrong
- A. Airspeed must be held constant based on the chosen best glide-type speed, not necessarily Vno, and clearing the engine is required.
- C. A minimum of three turns is required, and the engine must be cleared periodically during the descent.
- D. Bank angle must vary to maintain a constant radius, not remain fixed at 45°.
Steep Spiral
A descending maneuver requiring a constant radius turn around a ground point, completing at least three 360° turns while clearing the engine periodically and maintaining a specified airspeed.
- Minimum of three 360° turns required
- Constant radius maintained by varying bank angle
- Engine must be cleared periodically; bank not to exceed 60°
Memory trick: Steep spiral = 'spiral staircase down,' constant circle, clear the engine as you go.