Definition
A course-reversal maneuver flown on an instrument approach in which the pilot, from the outbound leg, turns 45° away from the outbound course, flies that heading for a set time (typically 40 seconds for category A aircraft, longer for faster aircraft), then makes a 180° turn in the opposite direction to intercept the inbound course.
Plain English
A way to turn the airplane around and line up with the approach course. You first angle off 45° from your current track, fly that for a short time, then make a tight U-turn the other way so you roll out heading back the way you came, lined up with the approach.
Context Anchor
Seen in instrument approach training and published procedures when a pilot must reverse course before continuing inbound toward the airport or a fix.
Derivation
"Procedure turn" because it is a charted, standardized procedure for reversing course on an approach. The 45° refers to the specific angle the pilot turns away from the outbound course before the 180° reversal. It is called "standard" to distinguish it from alternative course-reversal methods such as the 80°/260° procedure turn or a holding pattern in lieu of a procedure turn.
Why Pilots Care
Provides a predictable, standardized method to reverse direction and align with an approach when radar vectors are unavailable, reducing the risk of disorientation or airspace violations.
Grounding Statement
Picture flying away from the course, making a shallow angle away from it, then turning back across to meet the course from the opposite direction.
Intuition Check
The 45° does not mean a 45-degree bank angle. It means the airplane’s heading is changed 45 degrees away from the outbound course before turning back inbound.
Example Sentence 1
After crossing the fix outbound, the pilot began a standard 45° procedure turn to reverse course and intercept the final approach segment.
Example Sentence 2
During the approach briefing the instructor emphasized completing the outbound leg timing before rolling into the 180-degree portion of the standard 45° procedure turn.