Home » Air » Spy Docs: The Difference Between the A-12 and the SR-71

Spy Docs: The Difference Between the A-12 and the SR-71

by John Reed on May 31, 2012

Ever wonder what the real difference between the CIA’s A-12 Oxcart Mach 3 spy plane and its legendary successor, the Air Force’s SR-71 Blackbird?

Well, these declassified documents from 1967 compare the two jets performance side by side. Basically, the Blackbird could carry a lot more spy gear and electronic countermeasures than the A-12 could. What Specifically could the SR-71 carry that the A-12 couldnt?

Here’s a quick breakdown.

On a single mission an SR-71 could carry:

  • two “technical objective cameras”
  • two “operational objective cameras”
  • one “terrain objective camera”
  • one “high resolution” side-looking radar
  • one infrared camera
  • one electronic and communications intelligence-gathering package
  • three electronic warfare (countermeasures) systems, “CFAX, APR 27 and System 13C”

While the A-12 could carry some of this gear individually, it had to swap out particular sensors per-mission, according to the report. This meant that the A-12 was lighter and could fly 2,000 to 5,000-feet higher than the SR-71 at comparative speeds. Still, this wasn’t enough of a performance gain to warrant keeping the Oxcarts in service alongside the Blackbirds whose increased sensor loads and better countermeasures made them more useful and survivable than the A-12s, according to the documents.

Click through the jump to read the report.


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{ 126 comments… read them below or add one }

Richard S. May 31, 2012 at 1:22 pm

I know there isn't really another need for one, but I would love to see another mach 3+ spy plane come out. Mach 5+ if they could. It's not about need for me, it's about the United States flipping the Chinese and Russians the bird and daring them to stop the flyovers.


kennot May 31, 2012 at 1:26 pm

i'm not american, but yes, that's the idea.


brianckramer May 31, 2012 at 1:36 pm

We almost can. The problems I've heard of almost all have to do with heat buildup/coating problems.


W.R.Monger May 31, 2012 at 4:03 pm

I work in the aerospace industry and 8 years ago I'd have a agreed that the thermal problems would prevent faster than Mach 3.5 (to .7ish) but there have been an explosion of new heat resistant/heat wicking/heat transference materials on the market. I personally made composite parts that could withstand turbine exhaust temps and pressures of 800 F consistently so the 5+ barrier is just a matter of money. Why go faster than a little more than an enemy if it costs more but doesn't give you an advantage that you don't already have? I’m sure this is the reasoning for not pushing the envelope on this. I even had the opportunity to work on a Mach 15+ power plant project which works but has no airframe to attach it to


Technoweapon June 1, 2012 at 11:23 am

You're correct. We have scramjet/ramjet tech which has taken us to Mach 5 but only for a few moments before the craft was destroyed.

The tech is there. It's a matter of materials and design now.


Tiger May 31, 2012 at 11:53 pm

We have Spy Sats & Drones. And God only knows what the X37 does?


kim June 1, 2012 at 3:01 pm

True, such a plane wouldn't make much sense. But I do like your attitude.


Rich August 4, 2012 at 7:00 pm

I hear that buddy!


coolhand77 May 31, 2012 at 1:54 pm

Officially the SR71 could do Mach 3+. Unofficially I heard rumors they had them up around 5+


bevel450 May 31, 2012 at 3:34 pm

There is nothing in the world of known physics that can support a such a claim. Excess alcohol however, will take you to warp speed.


Justin Garak June 2, 2012 at 11:00 pm

Jim Bean Black


Dfens May 31, 2012 at 2:06 pm

What the hell kind of country is this that would retire the SR-71 and keep that POS U-2? It's sure as hell not the country I grew up in.


Pedro May 31, 2012 at 3:42 pm

A country with a lot of very high resolution spy satellites and possibly a secret follow-on program.

I think they decided that they needed only 1 high altitude reconaisance type and they selected the cheapest one. Mach3 is not required if you can supress hostile action some other way.


Dfens May 31, 2012 at 11:11 pm

The U-2 was crap when it was replaced by the SR-71 and it is crap now. Hell, they already have a satellite link to download the pictures they take. How much more bandwidth does it take to run the damn thing from the ground? About none. What a damn joke.


Tiger June 1, 2012 at 12:00 am

Crap is a strong word, but I agrree it should been retired. I don’t see why the USAF loves it over the Global Hawks? Both the SR & U-2 are not cost effective birds today.


bevel450 June 1, 2012 at 12:34 am

Cost, cost, cost !

kim June 1, 2012 at 3:05 pm

Ok, let's call a spade a spade: Given the choice between the two planes we really want the SR-71- not because it's more cost-effective, but only because it looks so incredibly cool, and goes so much faster than the U-2.


Dfens June 1, 2012 at 4:40 pm

Isn't the world so much better off now that it's run by women?


kim June 3, 2012 at 4:24 pm

Ahem, you thinking of Angela Merkel? Sarah Palin didn't make it to The White House….

John May 31, 2012 at 9:36 pm

Also, the U-2 Is incredibly cost effective, especially compared to the SR-71. Similar to putting the Google Street veiw equipment on a Ferrari vs. a Ford Focus. I've heard the per-image price of both platforms, and it's a significant difference. If it was too expensive in spend out your @## period, you can believe it's way to expensive now. I agree that a tactical/theater level ISR asset that's capable of overflying enemy territory would be awesome though, and is definitely needed.


Dfens May 31, 2012 at 11:08 pm

Oh yeah, the U-2 is the most cost effective way to transfer money from the US tax coffers to the accounts of Lockheed Martin ever.


bevel450 June 1, 2012 at 12:33 am

The customer….the USAF..likes the capability and operating economics of the U-2, not to mention the purI chase cost. The U-2's were paid for years ago and the cost of operating even with a pilot, is less than the cost of the Global Hawk.

Put down your drink and try to see it the way the Air Force does. As a tax payer, I love it.


Dfens June 1, 2012 at 4:42 pm

The customer likes the fat paychecks they retire to thanks to you sucks.

tiger June 1, 2012 at 4:48 pm

There is no need for a manned photo bird any more.

TrustButVerify June 5, 2012 at 10:39 am

Further down on the thread you seem to be saying that it wuz so the dirty contractors could keep lining their pockets, and that the savings of retiring the one and not the other were illusory.
Since you generally present yourself as having an aerospace professional background, I'm hoping you can provide specifics of how the U-2/TR-1/et.al. are more costly than the Blackbird, especially from an O&M standpoint. It would be a nice change from your usual carping about 10% contractor profits and how our platforms need to be more intimidating to the troglodytes.


exLoader June 5, 2012 at 11:02 pm

Who said we actually retired them. I might be mistaken, but I believe they're in long term storage at Davis Monthan AFB (the Bone Yard) along with the B-58 Hustlers, our first supersonic bomber, from the sixties. Just because we don't fly them anymore, doesn't mean they've been chopped up and sold for scrap….


TrustButVerify June 13, 2012 at 10:53 am

In the AMARC sounds retired to me. How many B-58s are flying right now?


T850 January 3, 2013 at 12:08 am

apples and oranges. u can't compare the SR71 to the U2. Educate yourself before you make yourself look like an idiot. If you truly understood the missions of each, you would never make a comment like this.


josh August 16, 2013 at 9:48 am
Mike May 31, 2012 at 2:21 pm

I've lived outside Beale AFB all my life, and grew up with the SR-71 flying by almost daily. I also heard the high-Mach rumors, but was told by someone that I know and trust, that the rumors were false…mach 3.2 was, and still is, the SR71's top speed. And isn't that fast enough for anyone wanting to do a photo-recon run? Nawwww…..


Technoweapon June 1, 2012 at 11:35 am

Speed was for evasion. I imagine it had to slow down, shoot the photos, then get the hell out ASAP before interceptors ate your lunch. 3.2 is incredibly fast.

As I remember it the SR71's plates, pipes, wires, etc, would all expand greatly due to the heat of friction at max speed. This caused high maintenance costs and long downtimes for the crafts that hit above Mach 3.

Rumors are still false. Due to our materials we're stuck in the realm of Mach3. But it's only a matter of time. We've hit Mach5 but only for moments before destruction. So the speed is there.


exLoader June 5, 2012 at 11:11 pm

….not if your taking picture from the edge of the atmosphere. How fast do you think a satellite moves ??? Do you think they slow a spy satellite down to take a snap shot ?? Not likely. Those kinds of aircraft and satellites are not the Top Secret part, it's the technology of those cameras.


Kurt May 31, 2012 at 2:30 pm

I've always been curious about the "A" prefix for the A-12. Doesn't "A" mean attack, as with the A-10 Warthog?


Richard May 31, 2012 at 3:35 pm

Aeroplane ;)


Ethan May 31, 2012 at 3:51 pm

The A- prefix in this case stood for "Article." Since it was concieved of as a black CIA program, they just used the internal Lockheed design number for this aircraft. A-12 was the 12th design concept. I believe that the A-11 was aerodynamically very similar, but without the RCS reduction techniques.


W.R.Monger June 1, 2012 at 9:26 pm

the program was called "Archangel" and that was supposedly where the "A" came from but "Article" is as good a source as any. back then as now when an aircraft is being developed the engine manufacturer wants an aircraft number and the use of "Test bed" or "Test article" was and is common as that takes away expectations of flight until all of the preliminary design work is finished and a company can risk a flight. even after first flight many companies still call them "Test beds" for whatever reason…


Charlie May 31, 2012 at 2:31 pm

The Mach 3 number is less than the 71's aerodynamic design limit.


bevel450 May 31, 2012 at 3:36 pm

Not true.

The immediate problem with such a claim is thermal. Heat soak from that 500-700F skin ( depending where it is on the airframe) is the real issue.

Heat soak…a reality


W.R.Monger May 31, 2012 at 4:09 pm

I work in the aerospace industry and 8 years ago I'd have a agreed that the thermal problems would prevent faster than Mach 3.5 (to .7ish) but there have been an explosion of new heat resistant/heat wicking/heat transference materials on the market. I personally made composite parts that could withstand turbine exhaust temps and pressures of 800 F to 1100F consistently for exhaust systems so the 5+ barrier is a matter of money.

Why go faster than a little more than an enemy if it costs a lot more but doesn't give you an advantage that you don't already have? I’m sure this is the reasoning for not pushing the envelope on this. I even had the opportunity to work on a Mach 15+ power plant project which works but has no airframe to attach it to.

It all comes down to money and what returns we will get from it.


Technoweapon June 1, 2012 at 11:38 am

Mach 15+ is a typo, I'm assuming.

Dear sweet Jesus I hope it's not a typo. :]


blight_ May 31, 2012 at 2:38 pm

For meaningless armchair giggles and apples to hearts of romaine comparison, compare the J58, F119 and F135.


W.R.Monger June 1, 2012 at 9:35 pm

i had a unique opportunity to see the F119 being tested in Florida at the Pratt & Whitney plant there. they burned that engine day in and day out constantly. at night it was pretty cool to see the sky light up when they hit the afterburner especially from teh top of the project we were working on at teh time. had a front row seat to a shuttle launch as well high above the treetops on our test cell. good times, good times…

also at the airfield where we built our test bed there was a J85 there that had a thrust diverter on it and it kicked out flames 90 degrees from exhaust (had titanium guide vains that diverted the thrust), that was pretty cool to see as well even though it was pretty much ancient technology :)


Black Owl May 31, 2012 at 3:55 pm

Sometimes I wonder if the SR-71 was ever capable of delivering a nuclear warhead and no one talked about it. The idea of being able to drop a bomb at mach 3+ without being touched must have been something that would strike fear into the Soviets and probably pushed them to make the MiG-25 Foxbat.


M167A1 May 31, 2012 at 4:15 pm

They looked at building weapons bays into the chimes…. Its not huge but could have held a SRAM or two.

The idea as I understood it was to appear just before the B-52s showed up on Soviet scopes and to hit air defense radars and fighter bases and otherwise wreak assorted havoc to disrupt Soviet Defenses so the B-52s could actually get to firing range.


bevel450 May 31, 2012 at 8:50 pm

No. That would have been impossible. There is only secondary structure out there….suitable for black boxes perhaps, but weapons.,…never. Most of the weapons carriage was expected to be in a rotary type launcher in place of the huge camera in the Q bay.

Interesting that several types of weapons were considered including realistic proposals for non explosive gravity bombs.


Dfens May 31, 2012 at 11:15 pm

Right, it would have been as impossible for the SR-71 to carry a nuke as it was for the aircraft to carry a drone on its back.


bevel450 June 1, 2012 at 12:36 am

Hey, ya gotta stop drinking and typing there Dfens.

Anyone who suggests that an airplane carry a nuke on it's back has an alcohol problem.

Guest August 27, 2014 at 1:47 am

Hahahahaha good one!! :-) Most do not even know this.

TrustButVerify June 3, 2012 at 4:24 am

In *Skunk Works* ol' Ben Rich said that his Skunk Works proposed an inert KE weapon for carriage by the SR-71. I got the impression that it would have ridden in a fashion similar to the D-21, although I could be off on that part.


bevel450 June 4, 2012 at 10:15 am

Put your thinking hat on before responding ! The D-21 was carried on the back ( top) of thme airplane. Are you suggesting that the Blackbird would drop the bomb after rolling into inverted flight ?

T-38C June 3, 2012 at 12:36 am

Some offensive capability was being designed into the SR-71 predecessor, the YF-12 though not air to ground. The AIM-47 was originally designed for the YF-12.


EJ257 May 31, 2012 at 4:18 pm

That’s what the XB-70 was suppose to do. Sadly that program was never completed and one of the test aircraft was lost during a photo-op of all things.


Smeghead May 31, 2012 at 5:00 pm

And the XB-70 was part of the the reason the Foxbat was developed in the first place. The A-5 Vigilante and B-58 Hustler were both capable of Mach 2, and the XB-70 was probably the last straw.

Even though the Valkyrie never made it past the experimental phase, the Soviets kept going with the MiG-25. It wasn't much more than a pair of engines with wings, but it still holds some all-time fixed-wing, air-breathing aviation records, including absolute altitude.


Riceball June 1, 2012 at 10:42 am

On the bright side, we got the F-15 out of it as a result of the scare the Foxbat gave us.


Black Owl June 5, 2012 at 11:53 pm

Yep, and the Russians got the Su-27 out of the scare the F-15 gave them so it worked out for everyone.

bevel450 May 31, 2012 at 8:51 pm

A Polaris sized warhead was considered.


tiger May 31, 2012 at 11:51 pm

That was the job the XB-70 was to be for.


blight_ May 31, 2012 at 4:13 pm

I didn't think that they did RCS testing at Groom Lake, but went looking, and found an interesting gem:


Smeghead May 31, 2012 at 5:04 pm

Oh, is that what they're up to in that photo? I was wondering what the hell they were doing to the aircraft, being upside down and all.

Great pic!


Societyinadownfall May 31, 2012 at 7:31 pm

Its amazing how we defeated Russia by pretty much outspending them during the cold war. Now history is repeating itself and we are defeating ourselves by spending more than we make.


blight_ May 31, 2012 at 10:58 pm

For decades the Soviets spent a huge portion of their GDP relative to us on their military. It was just a matter of time.


Guest August 27, 2014 at 1:52 am

But no one honestly wants to acknowledge this. Every new scare gets money thrown at it, if it raises enough stink. It is sad, but, OBL may be smiling from down there. After all, 911 costs less than $250K, but look at how much we have spent, and are still spending. And the Irag war, what a waste. 2 $trillion and counting. And all those poor soldiers who lost their lives, limbs and futures…..just a travesty on our leaders.


johnysmith May 31, 2012 at 10:42 pm

As pilots we are always interested in aircraft, and in particular unique and interesting aircraft. The SR-71 is one of the most fascinating aircraft ever build. http://airsoc.com/articles/view/id/4f717b6ec6f8fa


Guest August 27, 2014 at 1:57 am

Yes, I loved that plane growning up. About 20 years ago, I used to manage a mattress store, and a customer came in, wearing clothing that led me to ask him if he worked on the SR71. He said that he used to be a pilot.

So, of course, I asked him, knowing he was limited in what he could tell me, but, when questioned about missiles shot at him, he said: Well, we just turned the throttle up a little, and….no problem. They would actually out run the missile, until it ran out of fuel, or was jammed. He didn't mention the jamming, but, I knew a little. Cool guy, but, if you can fly a SR71, you have to be!! hahahahaha


deleted6399689 May 31, 2012 at 10:53 pm

A late friend of mine worked in the Skunkworks on everything from P-38's to the A-12 / Blackbirds and retired in the '70s. He had a lot of cool stories to tell and some he wouldn't. I asked him one day. long after he retired, how fast the SR-71 would go balls out. He said "I don't know and I'm not sure there are more than a dozen people that really do, but I installed the Mach meters in all of them and the meters will read over Mach 4."


bevel450 June 1, 2012 at 12:38 am

Well, lots of us worked out there and many dozens flew the aircraft. The only time the plane ever went Mach 4 was during drinking sessions with Navy pilots.


desertrat46 June 4, 2012 at 10:18 pm

Nice bit of snark on your part but his statement was that the Mach meters would read over Mach 4, not that the aircraft had done that. If you have access to all classified info on SR-71 missions and performance how about sharing?


Bealevet July 25, 2013 at 1:35 pm

My boss at Beale AFB in 1989 was a crew chief on the SR. After SR flights they had to go to debriefs where the pilots and support people (Life support, Avionics, etc) were briefed on the flight in general. One of the questions always asked was max speed due to different inspections that were required depending on the speed reached during the mission. On one flight the pilot was asked his max speed. Instead of replying mach 3, 3.1, 3.2 as per normal, the pilot looked around the room and told the debriefer "I'll speak to you after the 'brief, but mach 4+".
I unofficially was told this by multiple sources over the years, that the SR was taken to 4+, but the big problem was it always required intensive inspections after such a high speed run and was not at all encouraged. Basically if you had to do it, do it. But try not too.


Natsuo March 26, 2014 at 10:28 pm

16a65nana156351cfcongratulations Laura, as usual you came up with something beuutifal that photographs so well. i love. everything you do, but, would love to see you do a layered acrylic album with pages that interact with each other like the anatomy charts on transparency paper in the encyclopedia that show a little more when you turn the page. i think that would be awesome. keep doing what you do. i love all your work nana 156 146


matheusdiasuk May 31, 2012 at 11:12 pm

The photo looks like a Naboo Star Cruiser from Star Wars new movies.


authormjlogan June 1, 2012 at 12:38 am

In a rather hair raising flight in 1986, the blackbird outran Qaddifi's missiles at 1.6 miles per second. Do the math, that's well beyond M3.2. Speed of sound is 1,126 ft/s or 768 MPH. I'm sure this speed is unofficial and undocumented, but the source is http://all-things-aviation.com/aircraft/the-black


Bob G June 1, 2012 at 1:43 pm

The speed of sound also changes with altitude, air temp, and other environmental factors.

At altitude, as air pressure (density) and ambient air temperature decreases less energy, in this case airframe speed, is required to displace the air and move through the air then to achieve the same relative speed (Mach) vice true ground speed,

Airspeed is measured in knots (nautical miles). 1 nautical mile is 6,076.1 feet.

At 80K (probably the minimal operating altitude for a run over, Mach is going to be about 580 knots.

So, they were doing in the region of 3.6 if the numbers are to be believed.


Mikle W June 1, 2012 at 2:43 pm

Not being argumentative, but I am trying to understand, and the SR-71 is something I've been interested in for a long time and rumors of incredible "unofficial" speeds abound.

So then Mach 1 is 580 knots at 80K feet. Mach 2 is 1160 knots and Mach 3 is 1740 knots

If the airspeed is 1.6 knots per second, that is 1.6 * 60 seconds/minute or 96 knots per minute. 96 knots per minute x 60 minutes / hour = 5760 knots per hour.

That seems a bit faster than Mach 3.6… Maybe this is why these rumors of unbelievable speed exist, because the math seems straight out of high school…


W.R.Monger June 1, 2012 at 8:34 pm

i was stationed up in Washington at Ft Lewis back in the early 80's and a few people that i knew had connections with the Blackbird folks and this is what we were told, the aircraft left the western Washington state border and was clocked crossing the New York state eastern border 54 minutes later. do the math and that is the actual ground speed. no altitude or temperature/pressure adjustments just flat out point A to point B speed. soinds to me it did a tad bit better than Mach 3+ :)


bevel450 June 2, 2012 at 11:07 am

Like all urban legends…..

Talk with the SR pilots. There are still ( literally) dozens of them alive and quite active. The urban legend of that particulary transcontinental speed record was debunked at many Blackbird Association meetings years ago.

Sorry…the California to D.C. record of four minutes over an hour is the best that it ever did.


Rob M October 17, 2013 at 1:25 am

I've read that text and you have it inverted, it was actually 1 mile every 1.6 seconds. Comes out to around 2250 mph which is in the mach 3.4 range (at altitude.) That's a minor error, but a huge difference as you had the thing going like mach 10, lol.


Stratege June 1, 2012 at 3:31 am

A-12 and SR-71 were the great engineering achievement of that time. But those birds wasn't "wunderwaffe" after all.
Blackbird with its relatively huge radar signature and straightforward manoeuvrability was not survivable against Soviet air defenses such as S-200 / SA-5 SAM (Mach 4 / 35 km max height / up to 300 km max range)


4FingerOfBourbon June 1, 2012 at 5:10 am

I'd say they are 100% survivable, since plenty were shot at but never shot down…


bevel450 June 1, 2012 at 8:58 am

Sort of. The whole point was to not repeat the experience of the U-2 and wait until it was shot down before changing the mission, or platform for the mission.


Riceball June 1, 2012 at 10:45 am

I always understood that they were largely immune to SAMs of the time because of the height and speed that if flew at. By the time a SAM got up high up enough to catch up to an SR-71 it had already spent the bulk of its fuel and didn't have enough left to catch up to the SR-71 speed wise.


bevel450 June 1, 2012 at 11:32 am

Airframe performance was just part of it. The real magic was the ECM packages that the aircraft carried from day one. There were several of them, and they were constantly updated.

The Blackbird was a total system.


Bealevet July 25, 2013 at 1:42 pm

Exactly Riceball. Along with the electronics countermeasures package they carried.


Lance June 1, 2012 at 2:43 pm

Its a pity that the U-2 lived on and the Blackbird died to politics in the early 90s may it live on in legend.


bevel450 June 1, 2012 at 6:12 pm

Lance, Capitol Hill politics had little to do with it. The real problem was within the Pentagon, where everyone loved the product, but who was going to pay for it ?

Lance, the Army didn't want to pay. The Navy sure didn't, and the CIA didn't offer any offsetting funds to train, operated and maintain such a huge program. I don't blame
the AF for wanting out of the program.

Or let's just put it this way. Nobody wanted to pay for it or it would be flying today.

Got money >

Everyone liked the product but the AF was tired ot paying the bills for the entire program, and I cannot blame them. If


gkam44 July 3, 2012 at 4:51 pm

It died because of cost. Its job could be done by ER-2 and satellites much cheaper. But they were flying A-12 variants a few years ago. I spotted them at Edwards AFB.


Scout March 27, 2014 at 12:49 pm

It’s always a relief when someone with obvious exretpise answers. Thanks!


BobSacamano June 1, 2012 at 3:19 pm

This may have been addressed, but to my understanding the A-12 was a single seater, while the SR-71 was crewed by a pilot and RSO…


bevel450 June 1, 2012 at 5:50 pm

Yes, you are correct. Here is the difference in their mission,and hence, design philosophy….

The A-12 was designed as a penetrating, over flight plaform such as the U-2.

The SR was designed as a standoff reconnaisance platform, and all of it's electronics ( and optics) were optimized for that. Sure,it would overfly places like Noko, Vietnam and Cuba, but it was optimized for standoff of Russia and China.


kim June 1, 2012 at 3:22 pm

Just like the 200 mpg carburetor.


bevel450 June 1, 2012 at 6:14 pm

Precisely. And I am sure that all of the enthusiasts above, have got one of those carburetors as well !


Guest August 27, 2014 at 2:07 am

HELL NO!! GM bought all of those up, and hid them away!@ Didn't you know that…..jeeeesssshhhh! :-)


RSweeney June 3, 2012 at 6:51 pm

More proof that looking good is the same a flying well.

Is there a better looking aircraft in history?


gkam44 July 3, 2012 at 4:38 pm

The XB-70, the White Beast was equal in admitted speed, and much larger. Sometimes I would go out the side door of the hangar, and find myself almost under it. They would walk it our the day before flights and park it there before flights.


Guest August 27, 2014 at 2:09 am

That was cool, but, I still think the SR71 is the baddest looking plane of all time. Just MHO, that's all. :-)


jcallends June 6, 2012 at 7:32 am

Where can I see the inner workings of an SR-71 engine?


bevel450 June 6, 2012 at 7:53 am

ggooogle J-58


jhouse June 18, 2012 at 8:11 am

The Blackbird used to regularly fly over North Korea in the 80s (and perhaps beyond). The North Koreans tried to shoot it down every time but the closest they ever got was miles away. It was basically like throwing a rock and tring to hit a bat with both eyes closed.


Guest August 27, 2014 at 2:09 am

That is probably why they are STILL pissed at us :-).


gkam44 July 3, 2012 at 4:33 pm

There are other differences in the birds that let us differentiate between them. The YF-12A had a drop-down vertical stabilizer that folded up to the left before landing.

The chines (the flaring sides), went all the way to the nose for the SR, as in the picture, but only to the nosecone for the YF-12A. There were two on the ramp at Edwards a few years ago I spotted with satellites.

We had all three variants at Eddies Airplane Patch 1966-67,and to see one flying with the XB-70 was a sight I could never forget.


gkam44 July 3, 2012 at 4:41 pm

I have a poor photocopy of the Operations Manual for an SR-71 in digital form.

Anyone want a copy?

It may take a day to find it. Or you could google the phrase SR-71 Operations Manual,


Ben Hazi July 10, 2012 at 1:53 am

Sad that they were decommissioned. I mean these are technological marvels , the US should have kept at least a few of them because who know what other roles they might be able perform. But in the end they just cost too much to maintain and that's what every expensive aircraft face.


ChadManAST October 10, 2012 at 11:34 am

Why is the plane upside down in the picture?


A. Tompkins January 30, 2014 at 12:48 pm

Because the radar looking at it was mounted on the top of a nearby hill and thus saw the bottom of the aircraft… just as it would look from a ground radar looking at the airplane in flight.


Jill Trotchie December 6, 2012 at 7:05 pm

please u lnow what kind of spies i was thinking about-hikers


Danny Ross August 14, 2013 at 7:25 pm

Great things just sometimes become obsolete. My guess is that, however fast the SR-71 went, or however high it flew, it was made obsolete by military satellite technology. You put up a satellite and it sits there, observing, until it dies. For a discussion of a possible replacement for the Blackbird, try http://www.spyflight.co.uk/The%20Future.htm


Craig September 5, 2013 at 9:29 am

I worked on the SR-71 at Edwards on the test force from 67 to 69. The max speed of the a/c was "CIT limited", that is 'compressor inlet temperature' Above that speed/temperature the compressor turbine blades start coming apart. We did all the testing, an the max that I saw on the charts that came back were 3.325 mach. People said it could go mach 4 or 5 is a bunch of bull. The idea that you could fly a lot higher is also bull. You might be able to zoom to 95 or 100k but it then has a cost also – that means gas, range, speed, down alt after the zoom might be 60k. The a/c is a camera platform, it is not a fighter.
Should we still have the SR because everything has an associated cost. We did not build many of these aircraft. Kind of like AFone should the president have a 747 or a Gulfstream or maybe a Cessna 182. A limited budget makes decisions for you in one area and then forces your decision in another area.


Craig April 9, 2014 at 2:34 pm

Another fact is the A-12 was built several years before the SR-71. While the exterior looks the same they are different. The SR has plastic and carbon exterior panels. Kind of like a corvette. The A-12 had aluminum panels. The A12 inlet was mechanical and the inlet "computer" was big and had lot of mechanical parts that moved. The radar in the nose on the A-12 was a dish that was about 5 foot tall. One of the pilots said the best "lock on" tha he had was about 110 miles. The radar in the SR was a SLR, SIDE LOOKING RADAR, the antenna was like a 6 – 8 foot long 2×8 attached on the ends of the antenna. It would then roll it back an forth with about 120 degree roll taking radar pictures of the ground.


Rob M October 16, 2013 at 5:52 pm

Yeah, I don't really understand the motivation of people trying to pretend the thing needed to go mach 5+ and there must be a big conspiracy blah blah blah.. you hit it on the head when you said it wasn't a fighter. It was optimized for a specific purpose, was gossamer delicate, and had to fly within narrow limits to avoid damage or destruction. As for the conspiracy stuff, it is trackable on radar despite the relatively narrow RCS, so just go ask the thousands of radar controllers all over the world spread throughout many different countries, friendly, enemy and neutral alike if they are all "not authorized to disclose the speeds" they witnessed. Jesus Christ..


jerry griffin January 27, 2014 at 4:15 pm

what happened to the new plane/wing concept that could not-would not stall. last I heard the inventor's had no offers from the u s gov't and had sold the design concept to a radio-control plane manufacturer


BobThe Dog January 29, 2014 at 2:59 pm

As an ex-BUFF-Keeper, and lifelong aviation enthusiast, I am more than sick to death of this jingoistic horsehockey bestowing every capabitltiy on the Blackbird short of warp drive. Per the late, great Kelly Johnson himself, 3.3 mach, with a 3.5 "option", after much re-work on BOTH(!!!) airframe and engines, WAS IT!! As a feat of engineering, the aircraft stands on its own extraordinary merits and needs no further embellishment. BTW, given the fact, per "Moore's Law", that its far easier to increase the speed of a fire control computer than an entire aircraft, as demonstrated by an F-15 intercept of the ultimate "high/fast target" a used up recon SATELLITE!!!!, speed is now moot.


Danny May 1, 2014 at 3:38 pm

I have often wondered if the Beatles song "Black Bird" was about the SR-71. Anybody know the answer?


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BobTheDog August 9, 2014 at 11:52 pm

Another point, not usually mentioned in go-arounds such as this about Blackbird capability is that BOTH(!!) it and the MiG-25 started out on the same shaky ground in that, in each case their engines (J-58 and R-15 respectively ) were never intended for the performance that would be demanded of them, and could not be used for either mission without first being modified beyond literally recognition. The Blackbird was lucky in that, even though they weren’t ready for the first test flight, requiring a temporary substitution of J-75′s, the folks at P&W did finally get all the bugs ironed out of the J-58 before its entry into service. The MiG was not so lucky, having to soldier on with deficient power plants, the real reason it only was able to gaze at the SR-71′s “tail lights” getting smaller, fast! Which makes me wonder if anyone has heard about a final version of the Mig’s R-15 engine, the “I coulda’ been a contender” R-15BF2-300, which not only had ALL(!!) its previous shortcomings resolved but also offered the bonus of THIRTY(!!!) percent more thrust, and with which the Foxbat, with a few airframe mods to accommodate the higher temperatures, like Wile E. Cuyote on ACME leg vitamins, (my favourite episode of that entire series), would have given the “roadrunning” Blackbird some serious competition? As I hear, they only slammed the new engine into a couple of stock airframes to see what it would do, set a couple of zoom climb to absolute altitude records, and then cancelled it in favour of the more electronic-capable Mig-31, Moore’s law carrying more weight (bad pun intended). Also, as regards SAMs, the issue was never the missile’s speed as NO(!!!) man-carrying air breather is going to ever “outrun”(??) a rocket propelled ANYTHING!! It was rather the inability of the primitive, and slow soviet fire control computer in the ground-based guidance system to correctly calculate the proper lead angle so that the SAM and the Blackbird arrived at the same place/altitude at the same time causing the missile to arrive at the required height but way behind the “target”, necessitating a “looping over-to-tail chase”, at which point the SAM simply ran out of fuel before closing the gap. Which is a completely different scenario from literally enjoying superior speed of flight altogether, as has been claimed not withstanding SAM capabilities of mach 4+!


BuffKeeper August 27, 2014 at 3:32 pm

Having seen any number of sources noting that the rate at which aerothermodynamic forces (aka HEAT!!!) increased with even the slightest increase in speed, from a mere 17 deg at 707/747 cruising speed, to 267 deg at the "mere" 2.05 mach of the Concorde, to 550+deg for the mach 3.0 B-70 Valkyrie, to over EIGHT HUNDRED(!!!!) deg at just the 3.3 acknowleged for the Blackbird, coupled with the frank admission by the folks at P&W that, upon ANY(!!) exceeding of the max compressor inlet temp (427 deg centigrade, the other numbers were farenheight), usually reached at around mach 3.25, they "could NOT(!!!) guarantee the structural integrity of the engines" , aka KA-BOOM(!!!), coupled with Kelly Johnson's noting the sheer magnitude of cost and effort required to just get to mach 3.5 from the Blackbird's established cruising speed, I must to having some trouble swallowing all these "tales" crediting what is indeed an absolutely marvelous craft in its own right with every capability from SSTO to warp drive. Simply because the instruments were calibrated to more than cover the flight envelope does not prove the actual extent of it, and, BTW, I would suspect the reason the A-12 is upside down in the photo is that it was the way craft were mounted on the pylon for stealth testing, as any number of pics showing everything from the F-117 to the Raptor, also on their backs would suggest.


bevel450 May 31, 2012 at 3:42 pm

Sorry Mitch, but a huge amount of work on the plane was done with computers, mainly the propulsion/aero integration.

Ah….the romance of the slide rule rules !


aerodog79 May 31, 2012 at 6:33 pm

Computers with less computing power that my smartphone?


Mitch S. May 31, 2012 at 9:36 pm

I was using a bit of hyperbole but (as aerodog79 pointed out) those computers together probably didn't have the power of an iPhone.
I remember one of the big selling points of the JSF idea was with
modern computers the plane could be designed "virtually" to speed up
the process and reduce errors.

Admittedly it's a bigger task to develop a mass produced machine to be sold at a low price than an exclusive "boutique" machine (such as a Ford Focus vs a Ferrari) but nobody wants Focus performance for a Ferrari price!


tiger May 31, 2012 at 11:50 pm

With punch cards & rooms of machines & magnetic tape. Yep, Stone age.


bevel450 June 1, 2012 at 11:27 am

Of course ! It meant for much harder work. FAR more time than it would now, but guess what…..far less time than it would take with a slide rule.


Peter Wiggins June 1, 2012 at 12:09 pm

Me thinks some people is missing the irony of Dfens, and other people knows a lot less of airspace industry that they think they know, when they say that maybe the reason behind the MiG-25 was the SR-71.

Lockheed D-21 (yep, the combo looks like the GI-Joe/Cobra toy of circa 1985)

North American XB-70 Valkyrie (the sum of all fears behind the MiG-25)


Dfens June 1, 2012 at 4:38 pm

I agree. They're saving us right into the poor house. How can you afford not to be the country that flies the SR-71? Our Air Force is run by a bunch of weak wristed panty waists that are so far up the asses of the contractors they serve they can't survive direct sunlight.


Dfens June 2, 2012 at 1:04 am

Because paying their damn bills doesn't qualify me to have an opinion?


bevel450 June 2, 2012 at 3:29 pm


That is very fine advice, which I took from my father and it has served me well. To wit: the debate here on how fast the Blackbird can fly. The thermal issue has been discussed pretty well.

Before he died of cancer, I was able to spend some time with Ben Rich who as the designer of the A-12/SR propulsion system ( also F-104 and U-2). Ben told me that the thermal problems were really just the start of the problems.

The inlet system of the aircraft was optimized for a 3.2 Mach cruise, and that it would not go over that speed. Cruise and top were pretty much synonymous. That was the magic of the aircraft.

At greater than design speed, the shock waves would not be placed correctly in relationship to the inlet spikes, and without that proper placement, the engines would "unstart" and then all hell lets loose.
Not only is the aircraft in a very high drag condition without the shock placed accurately, but certainly asymetric thrust would ensue. Those compressors worked within a very, very narrow band of inlet pressure.


bevel450 June 4, 2012 at 10:12 am

Yes, an uninformed opinion.


TrustButVerify June 5, 2012 at 9:13 am

Nothing of the sort! I just chased down the reference- it's on page 226 of *Skunk works* (viewable using the "search inside" feature on Amazon for the term "creation of an energy bomb") which describes the concept as simply dropping a ton of steel. The previous line mentions Kelly Johnson's idea of using the Blackbird to launch single ICBMs, which must have become mixed up in my memory.


Guest August 27, 2014 at 1:49 am

Hahahahahaah yeah, and every one is now happy. Well, some :-)


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