(SR-71) J-58 POWER PLANT

This webpage has some exellent images of the SR-71's
j-58 Pratt and Whitney engine.




J-58 Engine Testing in Afterburner at Lockheed Martin Corp.





www.wvi.com...

I used that page for my own SR-71 page a few years ago.
The most funny thing about the engine is, the fuel it uses. They threw a matchstick in a bucket of JP-7 fuel, and it actually went out, instead of igniting it
That's one beast of an engine, a class of its own

Zion Mainframe


I beleive when the plane is cold it leaks fuel all over the runway.

So just as well it doesn't ignite too easily.

I read about that. I think it had something to do with the tanks expanding in flight?

QUOTE:


You've probably heard the SR-71 is a severe leaker, and I'll try to put this into perspective. Once LN2 is serviced a few hours prior to launch, the fuel system becomes pressurized, and that's when the real leaks start. Normally, about five or six steady fuel leaks (about the width of a drinking straw) show up coming from both inboard wings, falling about six feet to the ground. The entire bottom of the fuselage becomes wet, and starts dripping onto the hanger floor. Some puddling starts to accumulate on top of the inboard wings, and at times runs off the wing onto the floor. In some bad leakers, fountains can be seen spraying upward from the top of the inboard wings, ranging anywhere from two inches to three feet in height. Usually, the really bad leaks occur when the aircraft is getting close to being sent to the Depot for an overhaul. How much fuel is actually lost prior to flight? It was a common practice to refuel the aircraft about four or five hours prior to flight. It was also standard to place about four to seven hundred pounds of JP-7 extra in the tanks to allow for this leakage. That's a loss of about one hundred pounds or sixteen gallons per hour. And folks, that's just for a standard fuel load. At times, due to lack of tankers, we would put considerably more fuel onboard, and launch her on a "rocket ride". When we did this, you could basically double the amount of leaks I've described. Why all the leaks? High temperature fuel sealant was especially designed for the SR-71, and there's no other substance known in existence to replace it. Once the aircraft is as cruise speeds, it tends to seal itself. The leaks I've spoken of do not jeopardize the safety of the aircraft, due to the high flash point of JP-7. In fact, a lit match thrown into it would just go out. Up until the late 80's, the fuel leaked was simply washed out of the hanger after the launch, and went into the ground. Due to environmental laws towards the end of the program, we started to catch the fuel in drip pans, dispose of it properly, and vacuum the residual from the floor. You could always pick out the guys who had participated in a launch. They smelled like JP-7, there hair was sticky looking, and fuel stains covered their uniforms. Many guys wore rain suits to eliminate this problem. Believe it or not, a half can of Coke added to the wash removed all the stains and smells from the clothing.


www.blackbirds.net...

Thanks Q. That clears it up.

Well the fuel of SR-71 like that of MiG-25 and MiG-31 must have quite high ignition temp as the planes would otherwise explode in air at high speeds as the skin temp of the MiG-25 at high speeds is more than +300c.. (in the nose..)

[Edited on 13-9-2003 by FULCRUM]

Triethylborane (TEB) is used to ignite the engines for startup and afterburner mode. It's quite vicious and burns in the air at anything above -5 celcius.

Oh, yes, and the fuel doubles as coolant fluid for the hydraulics and oil! It's also thought to be a secondary coolant on the Aurora.

[Edited on 13-9-2003 by Lampyridae]

I like the look of this engine, very cool.

Big. Noisy. Guzzles fuel. Fun for the whole family!

What kind of engine is that quaneeri?

Its not the Pegusus is it?

DeltaNine.

It is the same engine as the first pic.

The SR-71 Engine.

This thread may be 20 years old, but the J58 article at Wikipedia provides deeper info on the genesis and early evolution of the J58 used to power the A-12 and SR-71:

The J58, company designation JT11, had its origins in the larger JT9 (J91) engine. It was a 3/4 scale JT9 with a mass flow of 300 lb/s (140 kg/s), down from 400 lb/s (180 kg/s). The JT11 was proposed to the US Navy under their designation J58. It was also proposed for various Navy and Air Force aircraft, e.g. Convair F-106, North American F-108, Convair B-58C, Vought XF8U-3 Crusader III, and North American A3J Vigilante, but none of these applications followed.

The J58 began development for the US Navy to power the planned Martin P6M jet flying boat. The P6M started out using Allison J71-A-4 engines and then switched to the Pratt & Whitney J75, due to J58 development delays. Upon cancellation of the P6M, it was selected for the Convair Kingfish and for the Lockheed A-12, YF-12A and SR-71. Other sources link its origin to the USAF's requirement for a powerplant for the WS-110A, the future XB-70 Valkyrie.