[Ref. Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 5-2]
Straight-and-level flight may be sustained at a wide range of speeds. The pilot coordinates AOA and thrust in all speed regimes if the aircraft is to be held in level flight.
The speed regimes of flight can be grouped in three categories: low-speed flight, cruising flight, and high-speed flight.
- Low airspeeds – Large AOA
- High airspeeds – Low AOA
As the thrust affects the airspeed, the AOA must also vary to maintain level flight.