SR71 Max speed?

[Exhaustgases]

No heating problems with the plasma system. Thanks for explaining how fast the SR has to be going at high altitude.

 

[Astro14]

No heating problems with the plasma system. Thanks for explaining how fast the SR has to be going at high altitude.

What is “the plasma system”?

How does it eliminate heat?

 

[Astro14]

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?

Sorry, this video is hard to watch.

A former Marine administrative clerk, with no flying experience, runs a YouTube channel, and in this video, he quotes a book, written by a Master Sergeant in the USAF, with no flying experience, who guesses at the top speed, and that is corroborated by an electrical engineer from Lockheed, who worked on the airplane, but has no flying experience, and has nothing to do with structures or propulsion.

A pile of rumor, sensationalized by those with no experience in high speed flight.

I have Brian Shul’s book on my shelf, and thoroughly enjoyed it, but consensus from other Blackbird pilots with whom I have spoken, is that he is a self-serving braggart, who likes to tell tall tales, and made a living telling those tall tales.

So, this video is a pile of unsupported supposition from those who were never there.

Also, he reiterates what I stated about compressor inlet temperature as the limit. 417C. It’s an engineering limit.

His comments about the F-15EX are just wild speculation, and he fails to take into account all of the considerations of high speed flight, like inlet efficiency, compression ratios, temperature limits, and drag.

Listening to an enthusiastic presenter doesn’t make the story true.

 

[Four Rings]

Sorry, this video is hard to watch.

A former Marine administrative clerk, with no flying experience, runs a YouTube channel, and in this video, he quotes a book, written by a Master Sergeant in the USAF, with no flying experience, who guesses at the top speed, and that is corroborated by an electrical engineer from Lockheed, who worked on the airplane, but has no flying experience, and has nothing to do with structures or propulsion.

A pile of rumor, sensationalized by those with no experience in high speed flight.

I have Brian Shul’s book on my shelf, and thoroughly enjoyed it, but consensus from other Blackbird pilots with whom I have spoken, is that he is a self-serving braggart, who likes to tell tall tales, and made a living telling those tall tales.

So, this video is a pile of unsupported supposition from those who were never there.

Also, he reiterates what I stated about compressor inlet temperature as the limit. 417C. It’s an engineering limit.

His comments about the F-15EX are just wild speculation, and he fails to take into account all of the considerations of high speed flight, like inlet efficiency, compression ratios, temperature limits, and drag.

Listening to an enthusiastic presenter doesn’t make the story true.

I appreciate that rank speculation and anecdotes are no substitute for data.

I met and spoke to MSGT Jim Goodall several times at the (now closed to the public) MNANG 133rd AW museum.

Jim was the driving force behind getting an A-12 out of mothballs at D-M AFB and put on display at the aforementioned museum. Because of Jim I was able to climb the ladder and peer into the (canopy opened) A-12 cockpit one sunny Minnesota summer day (at the time I was on temporary technician status with the 109th AES). As a non-pilot I had no idea what I was looking at, however.

That A-12 was later usurped by the CIA and is now on display at the CIA Langley HQ.

Jim had some access to former SR-71 pilots and technical experts during the restoration of the A-12 and the writing of his book; so long as he properly cited and quoted those folks, I’m inclined to think the information is worthy of consideration. Of course everything was written and edited to sell the speed aspect of the machines to the enthusiastic reader.

 

[Astro14]

I appreciate that rank speculation and anecdotes are no substitute for data.

I met and spoke to MSGT Jim Goodall several times at the (now closed to the public) MNANG 133rd AW museum.

Jim was the driving force behind getting an A-12 out of mothballs at D-M AFB and put on display at the aforementioned museum. Because of Jim I was able to climb the ladder and peer into the (canopy opened) A-12 cockpit one sunny Minnesota summer day (at the time I was on temporary technician status with the 109th AES). As a non-pilot I had no idea what I was looking at, however.

That A-12 was later usurped by the CIA and is now on display at the CIA Langley HQ.

Jim had some access to former SR-71 pilots and technical experts during the restoration of the A-12 and the writing of his book; so long as he properly cited and quoted those folks, I’m inclined to think the information is worthy of consideration. Of course everything was written and edited to sell the speed aspect of the machines to the enthusiastic reader.

My kid brother, a former USAF pilot, by the way, has every book on the Blackbird and has made “pilgrimages” to most of them, including the “big tail” in Alabama, the M21 mothership in Seattle, and others.

I’ve read all of his books, and I’m sure that I’ve read that one, as well. It’s a good book.

I loved Brian Shul’s book when it came out. Great stories. LA speed check is one of my favorites.

Years later, when the flight manual was declassified (partly), I realized that Brian might be, well, “stretching” things a bit. The former Blackbird pilots with whom I’ve spoken said, rather bluntly, that he did.

I dislike conjecture, though, and object to hearing stories about how it flew from people who haven’t flown it.

 

[billt460]

Astro, if the air at 18,000 ft. Is 50 percent less dense than at sea level, would your indicated airspeed be half that than it is at sea level? All other things equal.

 

[Owen Lucas]

could the boys of today do what was done back then? Not sure, but what is for sure is that in many ways computers have made us stupid, or at least lazy.

I bet they can do it by hand no problem. Engineers are a unique type, some of them would probably love doing it that way too. Might take 10x longer though.

 

[IndyFan]

Sorry, this video is hard to watch.

A former Marine administrative clerk, with no flying experience, runs a YouTube channel, and in this video, he quotes a book, written by a Master Sergeant in the USAF, with no flying experience, who guesses at the top speed, and that is corroborated by an electrical engineer from Lockheed, who worked on the airplane, but has no flying experience, and has nothing to do with structures or propulsion.

A pile of rumor, sensationalized by those with no experience in high speed flight.

I have Brian Shul’s book on my shelf, and thoroughly enjoyed it, but consensus from other Blackbird pilots with whom I have spoken, is that he is a self-serving braggart, who likes to tell tall tales, and made a living telling those tall tales.

So, this video is a pile of unsupported supposition from those who were never there.

Also, he reiterates what I stated about compressor inlet temperature as the limit. 417C. It’s an engineering limit.

His comments about the F-15EX are just wild speculation, and he fails to take into account all of the considerations of high speed flight, like inlet efficiency, compression ratios, temperature limits, and drag.

Listening to an enthusiastic presenter doesn’t make the story true.

Those people were probably all they could get, and all they can do is guess, really. I assume any pilot still alive who actually flew it cannot and will not say a thing about the top speed beyond the published Mach 3.2.

I didn't even watch it.

Love the Blackbird, though. I had a cool poster of it on my bedroom wall growing up. Right next to Farrah Fawcett! LOL!

 

[Dave Hess]

All aircraft have their design limitations and Astro14 does a great job explaining this with his very impressive resume and experience.

I would have loved to be a part of the Blackbird program.

 

[Astro14]

Astro, if the air at 18,000 ft. Is 50 percent less dense than at sea level, would your indicated airspeed be half that than it is at sea level? All other things equal.

That’s the right idea, though the math is a bit more complex, and takes into account temperature, humidity, and compressibility, and probably a few things I can’t remember.

So, from what I see on the gauge, (the very definition of indicated airspeed), at 18,000 feet, Indicated is a bit more than half the True Airspeed, but yes, that’s the idea.