Flight at speeds below maximum endurance requires what adjustment?

When flying at speeds below maximum endurance, the appropriate adjustment involves applying higher power and decreasing airspeed. This is because the aircraft's engine operates more efficiently at a certain speed where lift and drag are balanced.

At speeds below maximum endurance, the aircraft tends to encounter increased drag relative to lift, which means that greater power is needed to maintain altitude and control. The design of an aircraft's performance curve indicates that when flying slower, power settings must be increased to counteract this drag and ensure the aircraft can stay aloft effectively. Conversely, airspeed must be decreased because exceeding maximum endurance speed leads to a higher fuel consumption rate, which is beyond the objective of achieving maximum endurance.

Therefore, increasing power allows the airplane to maintain its altitude and achieve better performance, while the focus is on flying at a more economical airspeed. This is in line with the principles of fuel efficiency and managing the aircraft's performance in relation to endurance flight.