Definition
The maximum airspeed at which the landing gear may be safely extended or retracted. Operating the gear above this speed can damage the gear doors, actuators, or the gear itself due to excessive aerodynamic loads during the transit between up and down positions.
Plain English
The fastest you are allowed to be flying when you put the gear down or pull it up. Go faster than this while the gear is moving and you can break something.
Context Anchor
You see VLO in the aircraft flight manual, pilot’s operating handbook, cockpit placards, and gear-extension or gear-retraction checklist procedures for retractable-gear aircraft.
Derivation
The 'V' comes from the French vitesse, meaning speed, used throughout aviation for airspeed limits. 'LO' stands for landing gear operating. Knowing the V-prefix pattern helps when reading any V-speed: V plus a subscript identifying which limit it refers to.
Why Pilots Care
Exceeding this speed while operating the gear can cause structural damage or mechanism failure.
Intuition Check
Do not read “operating speed” as the aircraft’s normal flying speed. Here it means the speed limit for the specific action of moving the landing gear up or down.
Example Sentence 1
Slowing to below VLO before the final approach fix, the pilot lowered the landing gear and continued the descent.
Example Sentence 2
Extending the gear above the landing gear operating speed risks damaging the doors and actuators.