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Opinion: SR-71 does not deserve its records.

There are many faster objects, including the X-15 and Shuttle. Both are faster than the Blackbird but do not count. Shuttle is a spacecraft but even during reentry, shuttle could not hit such speeds unaided by other aircraft that departed from it along the way (the boosters etx). Nor could the X-15 which was dropped from a larger carrier aircraft. Both could not get to their records speed unaided.

Neither could the SR-71/YF-12. They burnt so much fuel getting off the ground that, to preform a run to top speed and get home, they needed to refuel. So how is that fundamentally different than Shuttle or the X-15? For an aircraft to qualify as an aircraft it should be able to get up and down without help. Therefore it is the Mig-25/31 that deserves the praise of "fastest aircraft".




This is an urban legend. Landing it when it was almost empty was gentler on the landing gear, so they took off with relatively little fuel in case the mission was scrubbed.

They could have taken off and accelerated to record-breaking speeds if that's all they wanted to do, but the typical mission profile was to fly to far away locations to conduct surveillance, so in-air refueling was always part of the mission profile.


That's not the information I've seen. From what I've read a fully-loaded takeoff and climb would burn so much fuel, far more than a typical profile, that it would still not have been able to break records set by the migs.


That sounds dubious to me. The SR-71 had some massive tanks and the idea that it couldn't accelerate to full speed on one tank seems unlikely. Even if you account for the burn in climbing to 50k feet ASL it seems like it has to be underselling the Blackbird quite a lot.


These two claims aren't mutually exclusive.


This article summarizes why they refueled after takeoff: https://theaviationgeekclub.com/former-sr-71-driver-explains...

TLDR: They needed full tanks (more or less) or an inert layer of nitrogen over the gas in the tanks before hitting Mach 3 or else the fumes in the tank might ignite. At the end you'll see that they had a system for fueling the tanks on the ground in order to hit mach 3 right after takeoff but it was a maintenance nightmare.

If I remember right, the SR71 could fly at Mach 3 for up to 90 minutes between refuelings. That's significantly longer than any jet ever made.


>> significantly longer than any jet ever made.

Except the XB-70. Data is rare, but it was to cruise at 3.0 for somewhere between one and two hours.


"Somewhere between one and two hours" sounds a lot like 90 minutes.




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