Quick Blackbird question for those in the know: There were a handful of trainer aircraft built in the A-12/SR-71 family, with raised rear cockpits for the instructor. Did this raised cockpit have much of an impact on top speed, or were the trainers as fast (or close to it) as the "regular" aircraft?

Per Rich Graham, former CO of the 9th SRW ("Boss Blackbird"), Kelly Johnson (the designer) once told him the airframe would be good for Mach 7 if engines could deliver it. He also thought that a J58-inspired build around an F135 wouldn't do much beyond get it up faster...

According to either Ben Rich's or one of Graham's books, the true speed limit is the Exhaust Gas Temperature--no higher than 860 degrees Fahrenheit or the engines will melt. To go faster, you need a higher-temperature engine, for one...

Diamondback

QuotePer Rich Graham, former CO of the 9th SRW ("Boss Blackbird"), Kelly Johnson (the designer) once told him the airframe would be good for Mach 7 if engines could deliver it.

That's entirely believable as the Convair Kingfish was stated by Robert Widmer (who worked for Convair) to have been capable of a maximum speed of Mach 6.25 - 6.5 (which was the A-12's competitor).


KJ

Here's a variety of concepts tested that eventually led to the Blackbird, scanned from Lockheed Blackbird: Beyond the Secret Missions by Paul F. Chickmore.  I posted them ages ago in a long lost thread and thought they belonged here:

did an interceptor version of the a12/sr71 ever enter service?
im arguing with somebody on youtube who claims the a12 was a vastly superior interceptor than the ee lightning 

it has better top speed but im pretty sure the lightning batters the sr71 on climb and acceleration, iv asked him about the climb rate etc and hes never answered me 

hes of the opinion top speed is absolutely all that matters with an interceptor
my point is there no point doing mach 3 but taking so long to get there that the bomber has already nuked your capital

There were only three YF-12s built IIRC, and none entered operational service as the project was cancelled in 1968.

The A-12 was the single seat predecessor of the SR-71/YF-12 and was a dedicated recce airframe.

No doubt your adversary on Youtube is American, so he would say that, wouldn't he? No doubt the YF-12 was faster but it also weighed a lot more than a Lightning, 120000 lbs v 45000 lbs. The engines of the YF-12 had about twice the overall thrust of the Avon 301s in the Lightning, 31500 lbs/engine v 16000 lbs/engine but a little time with a calculator should prove to him that the Lightning's thrust loading is about 35% better than the YF-12's, 1.4 lbs weight/lb thrust for the Lightning v 1.9 lbs weight/lb thrust for the YF-12.

How many vids has he seen of YF-12s rocketing vertically off the runway after a QRA? Answer = None......

Quote from: eatthis on April 10, 2013, 09:25:58 AMim arguing with somebody on youtube who claims the a12 was a vastly superior interceptor than the ee lightning 
it has better top speed but im pretty sure the lightning batters the sr71 on climb and acceleration, iv asked him about the climb rate etc and hes never answered me 
hes of the opinion top speed is absolutely all that matters with an interceptor
my point is there no point doing mach 3 but taking so long to get there that the bomber has already nuked your capital

I have a vague recollection of someone (almost definitely either Bill Gunston or Brab - Roy Braybrook, probably Brab when Air International used to be a must-read) writing about an interceptor variant.
The comment that sealed the "superiority" of the SR-71 was - sure, it would need the speed just to catch up with whatever launched an hour earlier that didn't require such a long and tedious pre-flight prep... And I think that it was a "comparison" between the "SR-71" and the F-4!.

Doesn't matter how fast the thing goes if it can't be launched on immediate demand.

Another problem that springs to mind is the missiles of the day.
Head-on attacks weren't quite so possible - how long (and what distance would it cover) would it take for an SR-71 to circle back onto a bomber target for a rear-quarter? Would it still be able to keep it in sight while setting up for such an attack?

Excellent youtube video explaining how the J-58s work in an understandable way, but without dumbing-down:

https://www.youtube.com/watch?v=F3ao5SCedIk

Quote from: Mr.Creak on April 10, 2013, 10:39:32 AM

Quote from: eatthis on April 10, 2013, 09:25:58 AMim arguing with somebody on youtube who claims the a12 was a vastly superior interceptor than the ee lightning 
it has better top speed but im pretty sure the lightning batters the sr71 on climb and acceleration, iv asked him about the climb rate etc and hes never answered me 
hes of the opinion top speed is absolutely all that matters with an interceptor
my point is there no point doing mach 3 but taking so long to get there that the bomber has already nuked your capital

I have a vague recollection of someone (almost definitely either Bill Gunston or Brab - Roy Braybrook, probably Brab when Air International used to be a must-read) writing about an interceptor variant.
The comment that sealed the "superiority" of the SR-71 was - sure, it would need the speed just to catch up with whatever launched an hour earlier that didn't require such a long and tedious pre-flight prep... And I think that it was a "comparison" between the "SR-71" and the F-4!.

Doesn't matter how fast the thing goes if it can't be launched on immediate demand.

Another problem that springs to mind is the missiles of the day.
Head-on attacks weren't quite so possible - how long (and what distance would it cover) would it take for an SR-71 to circle back onto a bomber target for a rear-quarter? Would it still be able to keep it in sight while setting up for such an attack?

The SR-71 had a turn radius in the hundreds of miles range. It was never meant for maneuvering. Many people agree the YF-12 was just a cover for the recon mission it was always meant for. To use the SR-71 as an interceptor you would have to know the exact path of the target at least the day before. Its an apples and oranges comparison so don't worry about it.

Lovely "White" bird 

Quote from: Mossie on April 10, 2013, 08:10:11 AM

I like this one.

Quote from: Zero-Sen on July 14, 2022, 04:02:35 AM

Which weapons would fit on the blackhornet?

Oh, so buildable...