Thread: Sled Driver- SR-71 Blackbird

One of the biggest limiting factors for top speed on the SR-71 was the Compressor Inlet Temperature had to remain below 427 degrees C and airspeed stayed below 420 knots indicated. If outside air temps were low it could go faster than the recommended top speed for short periods of time but was not advised. Unless of course you had a SAM up your butt and you pushed the jet harder than allowed to get yourself out of a jam - which happened a few times apparently!

There were several studies done to increase the sustained top speed to past Mach 3.5 but they were considered not necessary as the gains were too small for the investment involved.

You might enjoy listening to him...

RFT 079: SR-71 Pilot Brian Shul | Ready For Takeoff - Turn Your Aviation Passion Into A Career on acast

A pic I took a few years back.

SR-71 Seattle by Ron Beckett, on Flickr

Originally Posted by p38arover

A pic I took a few years back. Regrettably, the uploaded image quality is not as good as on my PC. I might try Flickr.

Attachment 127413

It came up well enough for me, Ron. It is just sad to see such a magnificent thoroughbred in a cage.

How did the SR71 compare to the XB70 Valkyrie in ceiling and speed? I have a photo somewhere of the lone surviving Valkyrie in the restoration shop at Wright-Patterson. Most impressive piece of metal.

Originally Posted by Bigbjorn

How did the SR71 compare to the XB70 Valkyrie in ceiling and speed? I have a photo somewhere of the lone surviving Valkyrie in the restoration shop at Wright-Patterson. Most impressive piece of metal.

Valkyrie was very impressive, the Blackbird does outperform it though. But given the Valkyrie was designed 10 years earlier, it’s at least as impressive IMO.

XB-70 Specs
Performance

• Maximum speed: 1,787 kn (2,056 mph, 3,310 km/h)
• Maximum speed: Mach 3.1
• Cruise speed: 1,738 kn (2,000 mph, 3,219 km/h)
• Combat range: 3,725 nmi (4,287 mi, 6,899 km)
• Service ceiling: 77,350 ft (23,580 m)
• Lift-to-drag: about 6 at Mach 2
• Wing loading: 84.93 lb/sq ft (414.7 kg/m²)
• Thrust/weight: 0.314

SR-71 Specs
Performance

• Maximum speed: 1,910 kn (2,200 mph, 3,540 km/h) at 80,000 ft (24,000 m)
• Maximum speed: Mach 3.32^{[N 5]}
• Ferry range: 2,824 nmi (3,250 mi, 5,230 km)
• Service ceiling: 85,000 ft (26,000 m)
• Rate of climb: 11,820 ft/min (60.0 m/s)
• Wing loading: 84 lb/sq ft (410 kg/m²)
• Thrust/weight: 0.44

Originally Posted by Homestar

Valkyrie was very impressive, the Blackbird does outperform it though. But given the Valkyrie was designed 10 years earlier, it’s at least as impressive IMO.

It's a pity it never really became an operational aircraft, as further development would have seen improvements. It's worth remembering it was intended to be a nuclear bomber, while the Blackbird was always going to be an unarmed spy plane.