A note:

"Inlet unstart" is a fairly dry description for a fairly dire problem that came up in the A-12 and was never truly solved for the SR-71. Any combustion process is basically a feedback loop where disturbing equilibrium one way or the other causes flame-out or detonation. "Unstart" was the euphemism Lockheed used for "one of the engines has flamed out." Each engine on the SR-71/A-12 produced approximately as much horsepower as the Queen Mary. The A-12 weighed a hair more than a Gulfstream G550 so as you might imagine, "yaw" is an understatement.

What happened next was worse: with one engine flamed out, the craft would yaw in the direction of the dead motor. This would cause the live motor to "unstart" in turn. The craft would then slow and the original dead motor would achieve proper air mix and reignite, slamming the craft the other direction. The end result of this process was a feedback loop much like water hammer in pipes, except at Mach 3 and 80,000 feet.

The test pilot fix was to pull both throttles to get the beastie back into the realm of both motors running simultaneously. The Lockheed fix was basically a force switch that would kill both motors if it detected radical, repetitive yaw. The A-12 was a single-seat spyplane; the major innovation of the SR-71 was adding a guy in the back whose basic job was to keep the throttles trimmed and deal with the fact that the motors liked to cut out with catastrophic effects.

b_b Tucumcari sighting