In the US Air Force SR stands for Strategic Reconnaissance. I do not know how they decide the number however. These are a few other US aerial vehicle abbreviations.
A= Attack
B= Bomber
F= Fighter
P= Patrol/Pursuit
AH= Attack Helicopter
What is SR71 auto insurance
Black
3.5
Boeing
the stratosphere!
2200 mph
2193 mph
Stratosphere
It is the Lockheed SR-71 "Blackbird", a reconnaissance aircraft.
The SR-71 is far faster.
No it just flew very high to avoid radar.
About 3 times the speed of sound. (3 mach)