Definition
A power-off, gliding maneuver in which the airplane is flown in a constant-radius descending turn around a point on the ground, using a bank angle that does not exceed 60 degrees at the steepest point. The pilot adjusts bank continuously to compensate for wind drift so the radius stays constant, and at least three full 360-degree turns are completed before recovery.
Plain English
A practice maneuver where the engine is at idle and the airplane glides down in tight, even circles around a chosen spot on the ground, with the pilot adjusting the bank to keep the circles the same size despite the wind.
Context Anchor
Seen in discussions of loss of control, emergency descents, and situations where a turn becomes too tight and the airplane develops a high sink rate.
Derivation
"Steep" refers to the bank angle required to keep the turn radius small, and "spiral" describes the descending circular path traced through the air as altitude is lost. Together they distinguish this maneuver from level steep turns and from gentler descending turns.
Why Pilots Care
Enables rapid altitude loss while remaining directly over a chosen landing spot and keeping airspeed under control.
Analogy
Like a corkscrew dropping straight down while turning around the same vertical line.
Grounding Statement
Picture an airplane circling over one spot while dropping rapidly lower on each turn.
Intuition Check
Do not assume a steep spiral is the same as a spin. In a steep spiral, the airplane is usually still flying around the turn; the danger is the tight turn, high descent rate, and limited room to recover.
Example Sentence 1
The instructor pulled the throttle to idle and asked the student to enter a steep spiral over the grass strip below.
Example Sentence 2
During the steep spiral the airspeed remained steady while the airplane descended in tight circles around the selected point.