Definition
The maximum airspeed at which the landing gear may be safely extended or retracted on a retractable-gear airplane. Operating the gear above this speed can damage the gear doors, actuators, or structure due to excessive air loads during the transit cycle.
Plain English
The fastest speed you're allowed to fly while raising or lowering the landing gear. Go faster than this while the gear is moving and you can break things.
Context Anchor
Seen in airplane flight manuals, checklist procedures, and cockpit placards for retractable-gear airplanes.
Derivation
The 'V' comes from the French 'vitesse,' meaning speed, used throughout aviation for V-speeds. 'LO' stands for 'landing gear operating' — the speed limit during the actual extension or retraction cycle.
Why Pilots Care
Exceeding VLO during gear transit can bend gear doors, damage hydraulic actuators, or cause a gear malfunction that forces an emergency landing. It's a different limit from VLE (gear extended) — VLO applies only while the gear is in motion.
Intuition Check
Do not assume VLO means any speed with the gear down. VLO is the limit for moving the landing gear up or down; the allowed speed after the gear is already down may be different.
Example Sentence 1
After takeoff, the pilot waited until the airspeed was below VLO before raising the landing gear.
Example Sentence 2
Exceeding VLO while retracting the gear can cause structural damage and require maintenance inspection.