VY, best rate of climb speed

VY is the designated airspeed for the best rate of climb. At VY, an aircraft gains the most altitude in the shortest time. Pilots commonly use it for the normal climb after takeoff when the aircraft-specific procedure no longer requires the steeper path associated with VX.

What it is used for

VY is an indicated airspeed and is normally published in KIAS. The approved POH or AFM controls the value and may list changes with altitude, weight, configuration, or aircraft variant. A VY value from a different aircraft is not a valid substitute.

Best rate and best angle answer different questions. VY maximizes altitude gained per unit of time. VX maximizes altitude gained per unit of horizontal distance. The pilot chooses the published speed that matches the operational objective and current aircraft procedure.

Example

After clearing a runway obstacle, a pilot follows the aircraft handbook's normal climb procedure and maintains the published VY for the relevant conditions. As altitude, configuration, or procedure changes, the pilot uses the handbook guidance rather than holding a memorized number indefinitely.

Why it matters

An incorrect climb speed changes climb performance, engine cooling, controllability, and traffic separation. VY is not a promise that the aircraft will achieve a particular climb rate. Density altitude, weight, wind, aircraft condition, and technique affect the result.

Use the applicable POH or AFM and current conditions. This entry explains the term but does not provide aircraft-specific performance data or an operational climb decision.

Related terms and tools

• VX, best angle of climb speed
• Indicated airspeed
• Density altitude