Originally Posted by
tartare
I think max speed the SR-71 attained was around Mach 3.5 - but Brian Schul reckoned he flew faster on the Libya mission.
Here's another source for SR-71 max speed from NASA historian Peter Merlin's Blackbird FAQ:
How fast could the Blackbirds fly?
The maximum design cruise speed was Mach 3.2. The speed was limited by structural temperature restrictions.
Fastest known flights:
YF-12A (60-6936) – Mach 3.14 (2,070 mph), USAF, official, 1 May 1965
SR-71B(61-7956) – Mach 3.27 (2,158 mph), NASA, unofficial, 14 December 1995 and 4 March 1997
A-12 (60-6928) – Mach 3.29 (2,171 mph), CIA, unofficial, 8 May 1965
SR-71A (61-7972) – Mach 3.32 (2,193 mph), USAF, official, 27 July 1976
https://www.nasa.gov/pdf/736495main_Blackbird_FAQ.pdf
Brian Shul's numbers sometimes seem to get better with age
as with his famous ground speed readout story:
https://theaviationgeekclub.com/sr-7...d-speed-check/