If you want to climb at the maximum angle of climb or endurance speed, you should fly at the same airspeed as which speed?

• A. Maximum L/D speed
• B. Best Rate of Climb speed
• C. Stall speed
• D. Minimum controllable speed

Answer: (A)

Maximizing climb efficiency means minimizing drag while maintaining enough lift, which happens at the airspeed where lift-to-drag ratio is highest. Flying at the speed for maximum L/D keeps drag minimal relative to the lift the wing produces, so the engine’s power can be used most effectively to gain altitude rather than fighting drag. That yields the steepest climb for a given forward speed (the best angle of climb) and also supports longer endurance because you’re operating at the most efficient drag/power point.

Stall speed and minimum controllable speed are near the low end of the envelope where drag climbs quickly and control margins shrink, so they don’t give efficient climb. The speed for best rate of climb focuses on vertical speed, which isn’t the same efficiency target as the maximum L/D condition.