When talking about the Lockheed Blackbird family, probably the most frequently asked Blackbird question is: How fast does it really fly?
It is well known that the SR-71 Blackbird spy plane holds the official record for the fastest jet-powered, piloted aircraft ever. The A-12 Oxcart, another Mach 3 high-altitude reconnaissance aircraft, served as the model for the SR-71.
For defense against supersonic bombers, the A-12 was converted into the YF-12, a high-altitude Mach 3 interceptor. The military never used the YF-12 as an operational aircraft. However, the YF-12 was also a forerunner of the SR-71 Blackbird reconnaissance plane.
Probably the most common Blackbird question when discussing the Lockheed Blackbird family is: How fast does it really fly?
“I’ve answered this question before, but here goes,” says Jim Goodall, former Master Sergeant at the U.S. Air Force and author of the book Lockheed SR-71 Blackbird: The Illustrated History of America’s Legendary Mach 3 Spy Plane. “The fastest an SR-71A has ever gone is Mach 3.43 in 974 [Blackbird #61-17974, better known as “Ichi-Ban”], at the time, a Site II bird. It blew out both inlets as it had a dual unstart.”
Goodall continues. “Ben Rich told me that the inlets were designed to fly at its “Sweet Spot” of Mach 3.24. All manned Blackbirds from the A-12 through to the last SR-71 built were designed to all fly at the same top speed.
“But during early flight testing at Area 51 with the A-12s, Jim Eastham told me that A-12 #128 flew as fast as any A-12 during testing. On the particular day that the A-12 red-lined everything.
“During a routine top-speed envelope expansion flight, A-12 #128 was having a hard time getting past Mach 2.7 as the outside air was too warm. The reason for the flight test card that day was to validate a new inlet bypass door schedule.
“Jim said he dropped the nose down a bit to see if he could at least reach Mach 3.0. Out of nowhere, Jim hit good air and in the dive with good air, he red-lined everything. He went into his descent profile and headed back to the test site.”
Goodall concludes:
“When all was said and done; and for a very brief 15 seconds, Jim hit Mach 3.56, or just under 2,400 mph. Mind you, this was a one-time event and was never duplicated.”
Linda Sheffield Miller (Col Richard (Butch) Sheffield’s daughter, Col. Sheffield was an SR-71 Reconnaissance Systems Officer), who runs Habubrats Facebook page, adds more details.
“The A-12, also known as Oxcart, altitude, and speed are unofficial because the A-12 remained top-secret until 1982. Ken Collins, A-12 pilot and SR-71 pilot [who also flew with Col. Sheffield], has revealed an altitude of 94,000 feet!
“The maximum design cruise speed was Mach 3.2. The speed was limited by structural temperature restrictions.
“The SR-71 flew faster than the rotation of the earth.”
She also lists the 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.”
Photo by Lockheed Martin
