Rate of Climb

Rate of climb tells you how quickly an aircraft can gain altitude when it has power left over after meeting the power needed just to stay level. The excess power is the part of engine output available to do "climbing work," and dividing by weight converts that available power into a vertical speed. Because heavier aircraft need more power to gain the same height per second, the same excess power produces a lower climb rate when weight increases.

Use this formula when estimating climb performance from engine power and aircraft weight, especially for piston aircraft or simplified performance problems. It is also useful when comparing how changes in loading, density altitude, or engine output affect climb capability.

• Using total engine power instead of only the excess power
• Forgetting to keep units consistent, such as mixing kW with N without converting to watts
• Confusing weight with mass and plugging in kilograms directly