Transonic airflow typically occurs in airplane speed regimes between Mach

• A. 0.60 and 0.95
• B. 1.20 and 1.60
• C. 0.50 and 0.99
• D. 0.75 and 1.20

Answer: (D)

Transonic flight involves flow that is subsonic in some regions and supersonic in others, with compressibility effects and shock waves becoming significant as you climb into this regime. This mixed flow typically starts around Mach 0.75–0.80 and continues up to about Mach 1.2, where the flow becomes predominantly supersonic and shock interactions dominate.

The range around 0.75 to 1.20 Mach best matches this transition zone, capturing both the onset of supersonic flow and the peak transonic effects without venturing too far into fully subsonic or clearly supersonic regimes. The other ranges either stay largely subsonic, begin well into supersonic flight, or miss the mixed-flow portion that characterizes transonic aerodynamics.