Definition
The speed range from Mach 5.0 to Mach 10.0, where airflow speeds are roughly five to ten times the speed of sound. At these speeds, aerodynamic heating becomes severe and air behaves very differently than at lower speeds.
Plain English
Speeds between five and ten times the speed of sound. Far faster than typical jet airliners, and into the range of advanced military and experimental aircraft.
Context Anchor
Seen in high-speed flight discussions, especially when the FAA handbook separates speed ranges such as subsonic, transonic, supersonic, and hypersonic.
Derivation
From the Greek 'hyper' meaning 'over' or 'beyond,' combined with 'sonic' from the Latin 'sonus' meaning 'sound.' Literally 'beyond sound' — used here to mean far beyond it, well past the supersonic range.
Why Pilots Care
Aircraft or vehicles at these speeds experience extreme heating from air friction, demanding special materials and design features.
Analogy
If supersonic is like stepping past a line, hypersonic is far down the road beyond that line. It is not just a little faster than sound; it is many times faster.
Intuition Check
Hypersonic does not mean just “very fast.” In aviation speed ranges, it specifically means about Mach 5 or faster.
Example Sentence 1
The textbook listed the four speed ranges as subsonic, transonic, supersonic, and hypersonic.
Example Sentence 2
At hypersonic speeds the aircraft skin must withstand intense heat buildup.