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Mach 3.5 Over Libya in an SR-71 Blackbird

thesr71blackbird.com

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Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#21
post #4

Is Mach 3.5 the highest reported speed? Is it "official" in some way?

Fastest official is Mach 3.43. I would note that that isn't likely the full story. The US Gov has famously been deceptive about the plane, both overselling or underselling its abilities. (Notably, I do not believe that the US Government ever 'officially' admitted to overflying the USSR.) It is very possible that for a short period of time, they sustained over mach 3.5 or 3.6, what affect that would have/had on the ai…

> At that speed, the engines are assumed to have been scraped after each flight. > One could make assumptions that the ram-jet elements of an SR-71's J-58s could allow for a few minutes...far beyond that

I would expect the SR-71 to stay at speed longer and for the engines to be capable of higher power (assuming the airframe and intake can handle it). US engines were generally higher quality, while Soviet engines were expected to be replaced very quickly relatively. However, this was a conscious decision on the part of the USSR: instead of making expensive engines with good maintainability in the field, they chose to make cheap engines that were easy to replace. As a result, while a MiG-25 may have only been able to maintain Mach 3 for a few minutes and ruin the engine in the process, they built 1,186 of them, with probably >5,000 Mach 3 capable engines.

Not particularly relevant, but always interesting to discuss how different people think

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#22

I love stories about America violating sovreign airspace, especially when they use such a cool plane. The entire world is truly their own backyard!

The days of America violating sovereign airspace are drawing to a close, thankfully.

“The United States-initiated aerial bombing of targets inside the borders of the Libyan Arab Jamahiriyah which took place on April 15, 1986, was met with substantial and immediate criticism by the world community. The positive reaction from the U.S. congress and the American public was not shared by much of the world. Arab nations denounced the American action, as did the Organization of Petroleum Exporting Countries. In meetings of the UN Security Council, countries denouncing the raid outnumbered those which supported it.

Good article: “American Bombing of Libya: An International Legal Analysis” (1987)

https://scholarlycommons.law.case.edu/cgi/viewcontent.cgi?ar...

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#24

Amazing what engineers were able to do (build aircraft like the SR-71) before computers came along and made them less productive.

I know you're being glib but I assume the reason we didn't do any more Blackbirds is because normal satellite imagery got good enough that it didn't make as much sense to keep building these crazy things.

Does anyone remember that satellite photo Trump leaked of that iranian missile silo?

https://www.npr.org/2019/08/30/755994591/president-trump-twe...

This one ^

I'm just guessing that if they showed it to Trump unprompted in a briefing, it's unlikely that this is max zoom. And it's already crazy clear.

And the article mentions:

"Hanham also says that the European company Airbus has been experimenting with drones that fly so high, they are technically outside the atmosphere and thus operating outside national boundaries. But she says she doesn't know whether the U.S. has such a system."

So I think we just got a bit better at radar deflection and flying really high to where the Blackbird doesn't make sense anymore.

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#25
Indeed, Mach 3.5 is the declared top speed in this story, but higher speeds are implied.

     The Mach eases to 3.5 as we crest 80,000 feet... Screaming past Tripoli, our phenomenal speed continues to rise... I realize that I still have my left hand full-forward and we're continuing to rocket along in maximum afterburner... The TDI now shows us Mach numbers, not only new to our experience but flat out scary.
He mentions unusually cool temperatures allowing higher speeds than usual, and the aircraft is performing better than ever. So who knows. 3.6? Did a perfect set of circumstances, mixed with a rather urgent need to depart, take them closer to 3.7?

It's truly incredible that the A12/SR-71 aircraft was designed without the benefit of modern computing. In Ben Rich's book "Skunk Works" I recall there a bit about a comment that somebody once made regarding Kelly Johnson, something like "That Swede can see air". Truly a compliment to Johnson's almost uncanny ability to design aircraft for a specification. The U2 was another example of such ability.

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#26
post #7

Earlier quoted context omitted.

I have read that story SO MANY TIMES, but I nearly always click and read again when it comes up.

Once you've finished re-reading, here's the reverse version: > There were a lot of things we couldn't do in a Cessna 172, but we were some of the slowest guys on the block and loved reminding our fellow aviators of this fact. People often asked us if, because of this fact, it was fun to fly the 172. Fun would not be the first word I would use to describe flying this plane. Mundane, maybe. Even boring at times. But th…

https://news.ycombinator.com/item?id=29373436

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#27
The dates in the story are confusing me.

> My first encounter with the SR-71 came when I was 10 years old in the form of molded black plastic in a Revell kit.

> Twenty-nine years later, I stood awe-struck in a Beale Air Force Base hangar, staring at the very real SR-71 before me.

> In 1962, the first Blackbird successfully flew, and in 1966, the same year I graduated from high school, the Air Force began flying operational SR-71 missions.

> I came to the program in 1983

So the author was born in 1944 if they were 39 (29+ 10) in 1983.

1966 then puts them graduating at 22 (was high school longer back then? I wouldn’t have thought so and he’s supposed to have a stellar record and 22 feels a little old for joining the military) and playing with the SR-71 model in 1952 before it was even conceived in 1960.

What am I missing?

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#28
Ironically, the plane was dripping, much like the misshapen model had assembled in my youth. Fuel was seeping through the joints, raining down on the hangar floor. At Mach 3, the plane would expand several inches because of the severe temperature, which could heat the leading edge of the wing to 1,100 degrees. To prevent cracking, expansion joints had been built into the plane. Sealant resembling rubber glue covered the seams, but when the plane was subsonic, fuel would leak through the joints.

Wouldn't this be a major hazard on the ground?

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#29

Amazing what engineers were able to do (build aircraft like the SR-71) before computers came along and made them less productive.

I know you're being glib but I assume the reason we didn't do any more Blackbirds is because normal satellite imagery got good enough that it didn't make as much sense to keep building these crazy things. Does anyone remember that satellite photo Trump leaked of that iranian missile silo? https://www.npr.org/2019/08/30/755994591/president-trump-twe... This one ^ I'm just guessing that if they showed it to Trump unpro…

>satellite imagery

"This one cool trick makes spy agencies hate him"

https://www.harborfreight.com/tarps

Re: Mach 3.5 Over Libya in an SR-71 Blackbird

#30
post #28

Ironically, the plane was dripping, much like the misshapen model had assembled in my youth. Fuel was seeping through the joints, raining down on the hangar floor. At Mach 3, the plane would expand several inches because of the severe temperature, which could heat the leading edge of the wing to 1,100 degrees. To prevent cracking, expansion joints had been built into the plane. Sealant resembling rubber glue covered…

You do what you gotta do. Spending millions per flight, you can have some guys in a golf cart with kitty litter follow the plane around the hanger.
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