The backseater later indicated slow speed of 155 knots, pilot saw 152 knots or 175 mph. The SR-71 at that point was gently floating down, control certainly would have been lost completely had not Blackbird pilot Brian Shul firewalled the throttles.

The SR-71, the most advanced member of the Blackbird family that included the A-12 and YF-12, was designed by a team of Lockheed personnel led by Clarence “Kelly” Johnson, then vice president of Lockheed’s Advanced Development Company Projects, commonly known as the “Skunk Works” and now a part of Lockheed Martin.

The Blackbird design originated in secrecy during the late 1950s with the A-12 reconnaissance aircraft that first flew in April 1962 and remained classified until 1976. President Lyndon Johnson publicly announced the existence of the YF-12A interceptor variant on Feb. 29, 1964, more than half a year after its maiden flight. The SR-71 completed its first flight on Dec. 22, 1964.

The Blackbird was designed to cruise at “Mach 3+,” just over three times the speed of sound or more than 2,200 miles per hour and at altitudes up to 85,000 feet.

When talking about the “Blackbird family” probably the most frequently asked Blackbird question is-how high and how fast does it really fly?

As you may remember we already answered this question HERE and HERE.

But what about the slowest speed ever recorded by a Blackbird?

‘I was flying the SR-71 out of RAF Mildenhall, England, with my backseater, Walt Watson. We were returning from a mission over Europe and the Iron Curtain when we received a radio transmission from home base,’ remembers Brian Shul, former SR-71 Blackbird pilot, in his book Sled Driver.

SR-71 print
This print is available in multiple sizes from AircraftProfilePrints.com – CLICK HERE TO GET YOURS. SR-71A Blackbird 61-7972 “Skunkworks”

Rex Lowe, former USAF Staff Sergeant, explains what happened later on Quora.

‘The aircrew was asked to make a low level pass of a British airfield where cadets were training. Having difficulty actually sighting the field, though navigation was dead on, the pilot, Brian Shul, realized the aircraft was below advertised flying airspeed, he lit the burners and darted off. The backseater later indicated slow speed of 155 knots, pilot saw 152 knots or 175 mph. The aircraft at that point was gently floating down, control certainly would have been lost completely had not Shul firewalled the throttles.’

This is probably the slowest speed ever flown by a Lockheed Blackbird.

However, after landing Shul and Watson were met by their commander.

Shul remembers;

‘We were both certain he was reaching for our wings. Instead, he heartily shook our hands and said the commander had told him it was the greatest SR-71 fly-past he had ever seen, especially how we had surprised them with such a precise maneuver that could only be described as breathtaking. […]Walt and I both understood the concept of “breathtaking” very well that morning and sheepishly replied that they were just excited to see our low approach.’

Photo credit: courtesy of Robin Harbour

Lockheed SR-71 Blackbird model
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