SR71 Max speed?

[Exhaustgases]

I really enjoyed the comments below the video.
Oh and no one mentions, that the higher it goes the faster it can go and it has to go faster to feed air to the air breathing engines. Then of course its also pretty chilly way up there too. So what is everyones educated guess on its max altitude and speed?

 

[oldhp]

I don't know, but that sum-beetch is a mooovin>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

 

[awguy]

I believe it once crossed the US in 64 minutes.

The YF-12A was going to be a fighter but who dogfights when your turns are the size of Texas.

 

[Exhaustgases]

Altitude guess. 300k ft plus.

 

[Revving2Redline]

I really enjoyed the comments below the video.
Oh and no one mentions, that the higher it goes the faster it can go and it has to go faster to feed air to the air breathing engines. Then of course its also pretty chilly way up there too. So what is everyones educated guess on its max altitude and speed?

It's the Bugatti Veyron of the air. Neat story on this amazing craft.

 

[wpod]

Faster than a speedy bullet.

 

[y_p_w]

The A-12 was supposedly marginally faster. But the SR-71 was built for longer range and more equipment.

 

[vavavroom]

Almost as fast as @AM on his way to the Chinese buffet.

 

[Pew]

Nothing is as fast as a 2003 Altima with 3 different colored panels.

 

[ripcord]

 

[Owen Lucas]

Possibly mach 4+?

Some interesting comments from YT:

@Tom-ej8eg​

5 days ago
Back in 1988 I had a girlfriend who was a USAF air traffic controller. She monitored the sea of Japan. She told me that SR-71's often flew across her airspace, but did not show-up on radar. SR-71 pilot's transmitted their position using Morris code. She said it was pretty easy to calculate their speed between position fixes. They crossed her airspace at 3,000 mph. I don't think anyone believes the SR-71 could only fly 500 mph faster then a stripped-down F-15 in full after-burner.

@docohm50​

1 day ago
I was 18 stationed at Beale AFB as a Avionics Instrument Tech back in 1982. I fixed all the instruments and did the "spike schedule" on the SR-71. The spikes could move 26 inches and the fwd and aft doors would open and close at different speeds and turns. We checked the system up to 85,000 ft and topped out at 3.2 mach on the spike cart(test equipment). Each SR-71 sortie had a formal debrief with the tech reps and the mechanics. For my shop we were interested in aerodynamic disturbances or engine stalls which usually occurred when the inlet spike and or doors were out of calibration for the speed, altitude, or AOA. We had recorded MRS tapes. This was like a EKG line across a paper. The altitude topped at 85,000 feet and the speed stopped recording at 3.2 mach. I saw many tapes of 3.2 mach. The Lockheed engineers never disclosed what the absolute top speed was they did say it was limited by the spike and the fwd and aft doors. I am 60 now and I am blessed to say I wrenched on the SR-71 for the first years of my AF career. This was a awesome video, thanks for bringing back memories. God Bless

 

[y_p_w]

Speed is supposed to be indicated air speed and not relative to ground. I guess it's nice having a stiff tailwind. Especially nice hitting a good jet stream.

 

[ripcord]

My folks were friends with a guy who flew C130's and he told a story of sitting on the tarmac on Hickam (on Honolulu) waiting for permission to taxi and hearing a Blackbird getting permission to take off. By the time he got a runway, taxied and got permission to take off, he heard the same Blackbird on approach requesting permission to land on the mainland. No idea if he was fibbing or not, though.

 

[MolaKule]

...I guess it's nice having a stiff tailwind. Especially nice hitting a good jet stream.

Do you really think the SR-71 flew at Jet Stream altitudes?

In terms of altitude, jet streams usually occur between 23,000 and 39,000 feet (7,000 to 12,000 meters) above the Earth’s surface. Each jet streams stretches for thousands of miles, but is only about 3 miles thick and a few hundred miles wide. Jet streams are strongest in the winter because temperature contrasts are greater.

The Jet Stream

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere, typically occurring around 30,000 feet (9,100 meters) in elevation. Within jet streams, the winds blow from west to east, but the band often shifts north and south because jet streams follow the...

www.noaa.gov

 

[y_p_w]

Do you really think the SR-71 flew at Jet Stream altitudes?

In terms of altitude, jet streams usually occur between 23,000 and 39,000 feet (7,000 to 12,000 meters) above the Earth’s surface. Each jet streams stretches for thousands of miles, but is only about 3 miles thick and a few hundred miles wide. Jet streams are strongest in the winter because temperature contrasts are greater.

The Jet Stream

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere, typically occurring around 30,000 feet (9,100 meters) in elevation. Within jet streams, the winds blow from west to east, but the band often shifts north and south because jet streams follow the...

www.noaa.gov

It definitely could get a tailwind. I was just thinking basing the speed on relative position to points on the ground didn't account for wind.

 

[burbguy82]

Amazing aircraft, no clue on top altitude and speed, I would guess 100kft , and 3000 mph airspeed

 

[Inked]

Ludicrous Speed

 

[Astro14]

Altitude guess. 300k ft plus.

Absolute fantasy.

The A-12 flown by the CIA flew a bit higher and faster.

Same motors. Less weight. Less drag.

Max altitude depended on aircraft weight, and air temperature, among other things. On a good, cold day (in the stratosphere- where temperature rises with altitude) the airplane would be on the higher side of 80,000 to 85,000 feet.

 

[Astro14]

My folks were friends with a guy who flew C130's and he told a story of sitting on the tarmac on Hickam (on Honolulu) waiting for permission to taxi and hearing a Blackbird getting permission to take off. By the time he got a runway, taxied and got permission to take off, he heard the same Blackbird on approach requesting permission to land on the mainland. No idea if he was fibbing or not, though.

Well, since the VHF/UHF radio doesn’t work beyond line of sight - which limits the range between surface stations to a few dozen miles when you’re on deck - and a few hundred miles if the transmitter is at 80,000 feet - there is no way he could’ve heard that radio call.

Even if he knew the destination (likely Beale) and the frequency on which to listen.

 

[jws555]

Slower than Maverick's "Darkstar".

Regards,
John