Definition
A pre-landing mnemonic checklist used by pilots of complex single-engine airplanes to confirm four critical configuration items before landing: Gas (fuel selector on the proper tank and fuel pump as required), Undercarriage (landing gear down and locked), Mixture (set rich for landing), and Propeller (set to high RPM / full forward for a possible go-around).
Plain English
A four-letter check pilots run through on final approach to make sure the airplane is set up to land safely — fuel on the right tank, wheels down, fuel mixture rich, and prop set so the engine can give full power if needed.
Context Anchor
Used in the traffic pattern or before final approach as part of the before-landing check.
Derivation
An acronym formed from the first letters of the four items it covers: Gas, Undercarriage, Mixture, Propeller. ‘Undercarriage’ is the older British term for landing gear, which is why the letter U is used instead of L.
Why Pilots Care
Helps prevent common landing accidents such as gear-up landings or engine failures due to improper settings.
Intuition Check
Gump is not a person or a slang insult here. In this aviation use, it is a checklist reminder for key items before landing.
Example Sentence 1
Turning final, she ran the GUMP check one more time and confirmed three green lights for the gear.
Example Sentence 2
The instructor reminded me to do my GUMP items before every landing.