In the region of normal command, what must be done to increase speed?

• A. Air density is independent of power changes.
• B. Power must be added to increase speed.
• C. Thrust has no effect on airspeed in this region.
• D. Speed automatically increases with angle of attack.

Answer: (B)

In the region of normal command, how fast the airplane flies is mainly controlled by engine power. Increasing power adds thrust, which pushes the airplane forward and speeds it up until the thrust minus drag reaches a new, higher equilibrium speed. So to raise airspeed, you must add power. Air density isn’t affected by power changes (it’s set by altitude and temperature), so that option isn’t relevant. Thrust does affect airspeed, so claiming it has no effect isn’t correct. Also, speed isn’t automatically tied to angle of attack in this region—adjusting AoA changes lift and drag, and speed isn’t guaranteed to rise just by changing AoA.