In a steady climb of 1000 fpm, if the pitch is increased to achieve 8000 fpm, what happens to the lift component?

• A. It increases
• B. It decreases
• C. It remains unchanged
• D. It becomes zero

Answer: (B)

Lift in a climb acts perpendicular to the flight path, while weight acts straight downward. In steady flight, the lift must balance the component of weight perpendicular to the flight path, which is W cos gamma, where gamma is the flight-path angle. As you pitch up to achieve a much steeper climb (from a gentle climb to 8000 fpm), gamma increases, so cos gamma decreases. That means the portion of weight that lift has to oppose becomes smaller, and the lift component decreases.

Note: the total lift produced by the wing can still change with angle of attack and airspeed, but the lift component used to counter the weight’s component perpendicular to the flight path decreases as the climb becomes steeper.