Did The US Air Force Lie About The SR-71’s Top Speed?

Recently, Boeing got into a bit of a controversy when it claimed that the F-15x could fly as fast as Mach 2.9 only to take that claim back a few days later. This prompted a resurgence of conversations on how the US tends to keep the maximum performance capabilities of its tactical aircraft a closely guarded secret.

The SR-71, for instance, despite its retirement a quarter of a century ago, still holds the title as the fastest reusable crude jet aircraft with a top speed of Mach 3.2. But several Blackbird pilots claim that it’s faster than its top speed.

Top Speed

According to the US Air Force, the SR-71’s top speed was  Mach 3.2 and according to the manual, pilots shouldn’t push the aircraft beyond Mach 3.3 as it is reaching the outside limits of its thermal and structural integrity.

However, there are several records of several SR-71s going beyond that limit. In one instance recounted by retired US Air Force Master Sergeant Jim Goodall in his book, one testing flight of Blackbird tail 974 reached as high as Mach 3.43. This is more than 175 mph faster than the stated top speed. But this isn’t the fastest account that was found.

According to former Blackbird Brian Shul’s accounts during Operation El Dorado Canyon in 1986, he pushed his SR-71 up to Mach 3.5 while outrunning Libyan surface-to-air missiles.

How Fast Was the SR-71

How fast was the SR-71, really? Several sources point to the aircraft being capable of achieving speeds as high as Mach 3.5 or maybe even faster.

However, it’s important to remember that this would exceed the safety limits of the compressor inlet on the aircraft J-58 turbo ramjet engines. Not to mention, pushing the fuselage’s thermal and structural limits. One thing that we can say for sure is that the plane was certainly faster than what it has been officially disclosed.