Climb, Best Rate of

Best rate of climb (V_Y) is the airspeed that produces the maximum altitude gain per unit of time. It is the standard climb speed used after obstacle clearance is assured, for efficient climb to cruise altitude.

V_Y and Density Altitude

V_Y (in IAS) decreases as altitude increases. At higher density altitudes, both the rate of climb and the V_Y speed (IAS) decrease. For high-altitude airports in summer, V_Y and overall climb performance can be significantly degraded — always check performance charts for the actual conditions.

V_YSE

On multi-engine aircraft, V_YSE (best single-engine rate of climb speed) is the blue radial line on the airspeed indicator. After an engine failure, reaching V_YSE is the first airspeed target to maximize climb performance on the remaining engine. V_YSE performance at maximum weight in ISA conditions at sea level is the published single-engine rate of climb in the POH.

Related Terms

See also: Best Angle of Climb (V_X), Density Altitude.