Which statement best describes the region of normal command?

• A. Power required to maintain altitude decreases with speed
• B. Power required to maintain or change speed increases with speed
• C. Power required stays constant with speed
• D. Power required is independent of speed

Answer: (B)

In the region of normal command, the amount of power the engine needs to maintain a given airspeed or to change speed increases as you go faster. This happens because drag increases with speed, especially parasite drag at higher speeds, so more power is required to overcome that drag as you command higher speeds. Therefore the statement that power required to maintain or change speed increases with speed is the best description. The other ideas—power required staying constant or being independent of speed, or decreasing with speed—don’t match how drag and power interact in cruise flight.