Definition
Hand propping is the procedure of starting an aircraft engine by manually rotating the propeller by hand to turn the engine over and initiate combustion, used when the aircraft has no electric starter or when the starter or battery is inoperative. The procedure requires a qualified person at the controls, proper chocking or restraint of the aircraft, correct throttle and mixture settings, and a trained person at the propeller using approved technique.
Plain English
Starting the engine by pulling the propeller through by hand instead of using the electric starter button. It's done when the starter doesn't work or the airplane was never built with one, and it must be done carefully because a spinning propeller can seriously injure or kill someone.
Context Anchor
Seen in starting procedures, especially for airplanes with no electric starter, a failed starter, or approved procedures that allow the engine to be started by hand.
Derivation
From 'hand' plus 'prop,' a shortened form of 'propeller.' The term reflects the early aviation practice — before electric starters were standard — of swinging the prop by hand to start the engine.
Why Pilots Care
Enables engine starts in remote locations or after electrical failure, yet demands strict safety steps because the propeller can cause severe injury or allow the aircraft to move unexpectedly.
Grounding Statement
When the propeller is pulled through with the engine ready to start, the airplane can go from still and quiet to running in an instant.
Intuition Check
Hand propping does not mean casually moving or checking the propeller by hand. It means using the propeller as the starting method, with the engine able to start immediately.
Example Sentence 1
With the battery dead at a remote strip, the instructor talked the student through hand propping the Cub while a qualified pilot held the brakes from the cockpit.
Example Sentence 2
During a remote field operation, the crew used hand propping to start the engine after the battery had drained.