FAA Private Pilot Airplane (PAR)Aerodynamics and Aircraft SystemsEasy
An airplane is in a stabilized climb at a constant airspeed and constant rate of climb. Compared to straight-and-level flight, which statement about the relationship between lift and weight during this climb is correct?
- ALift must be greater than weight to sustain the climb
- BLift is slightly less than weight because a component of weight acts along the flight path
- CWeight becomes negligible once thrust exceeds drag
- DLift and weight are exactly equal, just as in level flight
Show answer & explanationAnswer & explanation
Correct answer: B. Lift is slightly less than weight because a component of weight acts along the flight path
In a stabilized climb, the flight path is inclined, so a component of weight acts rearward along the flight path (opposing thrust) rather than being fully supported by lift. Thrust must exceed drag to overcome this weight component and gain altitude, while lift is slightly less than weight.
Why the other options are wrong
- A. Lift does not exceed weight in a stabilized climb; thrust provides the extra force needed.
- C. Weight is never negligible; it still acts vertically downward at all times.
- D. This is only true in level flight, not in a climb.
Forces in a Climb
In a stabilized climb, thrust exceeds drag to overcome the rearward component of weight along the flight path, while lift is slightly less than total weight.
- Climb flight path tilts the weight vector
- Thrust > Drag sustains the climb
- Lift is slightly less than weight, not more
Memory trick: Climbing tilts the scale — weight leans back onto thrust.