A pilot who intends to maintain level flight must coordinate the angle of attack and thrust.

• A. Coordinate the angle of attack and thrust.
• B. Adjust the bank angle and rudder to maintain level flight.
• C. Change airspeed while keeping thrust constant.
• D. Vary flap setting to maintain altitude.

Answer: (A)

Maintaining level flight comes down to balancing the forces acting on the airplane: lift must equal weight and thrust must equal drag. The angle of attack is the primary lever for setting lift at the current speed and weight, while thrust controls airspeed and the resulting drag. By coordinating the angle of attack (to hold the required lift) with the thrust setting (to balance drag and keep the desired speed), you can keep the airplane at a steady altitude and level flight path. The other choices describe actions more relevant to turning, changing speed with little or no thrust change, or altering lift-altitude behavior with flaps, which isn’t how you sustain straight-and-level flight.