Definition
The airspeed that produces the greatest gain in altitude per unit of time. Flown in a clean configuration with the engine at full power, VY delivers the maximum vertical feet-per-minute climb performance the airplane is capable of under the existing conditions.
Plain English
The speed that gets you the most altitude in the least amount of time.
Context Anchor
You will see VY during takeoff and initial climb discussions, especially after lift-off once obstacle clearance is no longer the main concern.
Derivation
Velocity' gives the V; 'Y' is simply the letter the FAA assigned to mark this specific climb speed. VY sits alongside VX (best angle of climb) — the two letters are labels, not abbreviations of words.
Why Pilots Care
Reaching a safe or assigned altitude as quickly as possible after takeoff improves options for engine failure, terrain clearance, and traffic avoidance.
Intuition Check
Best rate does not mean the steepest climb path over the ground. It means the fastest altitude gain per minute; the steepest climb path is a different speed.
Example Sentence 1
After lift-off and once clear of any obstacles, the pilot pitched for VY to reach pattern altitude as quickly as possible.
Example Sentence 2
The performance chart showed that maintaining best rate of climb speed allowed the aircraft to clear the 1,000-foot obstacle well before the runway end.