Definition
Flight at speeds where the compressibility of air becomes a significant factor in aircraft performance and handling, generally at or above the transonic range (around Mach 0.75 and faster). At these speeds, airflow over parts of the aircraft can approach or exceed the speed of sound, producing shock waves and aerodynamic effects that do not occur at lower speeds.
Plain English
Flying fast enough that the air itself starts to behave differently — it can no longer flow smoothly out of the way, and that changes how the aircraft handles.
Context Anchor
Seen in discussions of thrust, drag, engine performance, and airplane performance at faster cruise or higher-speed operating conditions.
Why Pilots Care
Correct thrust management and awareness of control changes are required to avoid loss of performance or stability.
Intuition Check
High-speed flight does not just mean “faster than usual.” In this context, it means fast enough that drag and airflow effects significantly change how much thrust the airplane needs.
Example Sentence 1
Pilots transitioning to jets must learn how high-speed flight affects control authority and stall behavior near the speed of sound.
Example Sentence 2
In high-speed flight the pilot watched thrust settings to counter the rise in drag.