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SR-71 exhaust radar sig
http://www.warthogterritory.net/forum/viewtopic.php?f=9&t=7521		 Page 1 of 1
Author:  30mike-mike [ 01 Nov 2004, 20:35 ]
Post subject: 
A friend of mine is interested in any verification of the last two sentences:


The development of the A-12 OXCART spyplane in the late 1950s created another problem for aircraft and engine designers. The high speeds reached by the A-12 would cause the skin of the aircraft to get hot. Temperatures on the OXCART ranged from 462 to 1,050 degrees Fahrenheit (239 to 566 degrees C). The wings, where the fuel was stored, had external temperatures of more than 500 degrees Fahrenheit (260 degrees C). Even with the lower flashpoint, fuel stored in the wings could explode. As a result, the engine designers at Pratt & Whitney sought a fuel with an extremely high flashpoint. Working with the Ashland Shell and Monsanto companies, the engine designers added fluorocarbons to increase lubricity (or slipperiness), and other chemicals to raise the flashpoint. The resulting fuel was originally known as PF-1 but later renamed JP-7. It was used only by the A-12 OXCART (and its sister YF-12 interceptor) and later the SR-71 Blackbird. JP-7 has such a high flashpoint that a burning match dropped into a bucket of it will not cause it to ignite.

Engine designers and fuel chemists created JP-7 with a high flashpoint that would not explode in the aircraft's tanks, but this also made the fuel hard to ignite within the engines themselves. Because JP-7 is so hard to ignite, particularly at the low pressures encountered at high altitudes, these planes used a special chemical called tri-ethyl borane (TEB), which burns at a high temperature when it is oxidized (combined with air). <b>Another problem that the A-12 encountered was that the engine exhaust (particularly shock waves created in the exhaust when the engines were at full afterburner) was easily seen by radar. The engine designers added an expensive chemical known as A-50, which contained cesium, to the fuel for operational flights that reduced its ability to be detected by radar.
</b>

"Live every day like it's the last, 'cause one day you're gonna be right!" Ray Charles (6/10/04 was the day)
Author:  boomer [ 01 Nov 2004, 23:29 ]
Post subject: 
afterburner exhaust is basically a plasma, it conducts electricity and has been trackable on RADAR for a long time on many planes. Cant confirm the "cesium" part though.

"We sleep safely in our beds because rough men stand ready in the night to visit violence on those who would harm us". George Orwell

Fighting For Justice With Brains Of Steel !
<img src="http://www.fas.org/man/dod-101/sys/ac/atengun2X.GIF" border=0>
Author:  30mike-mike [ 02 Nov 2004, 00:37 ]
Post subject: 
Thanks boomer.<img src=icon_smile_big.gif border=0 align=middle>

"Live every day like it's the last, 'cause one day you're gonna be right!" Ray Charles (6/10/04 was the day)
Author:  M21 Sniper [ 03 Nov 2004, 19:28 ]
Post subject: 
Another problem with the SR-71 was that if you actually found it, you just accomplished the easy part.

Intercepting it was an entirely different matter.

"Molon labe".
Leonidas, King of Sparta,
Thermopylae, 480 B.C.
Author:  gifted [ 03 Nov 2004, 19:48 ]
Post subject: 
Does ANYBODY have a missile that can concievably hit the thing?

"Some pup"
Nickname by Fenderstrat72
Author:  boomer [ 05 Nov 2004, 12:43 ]
Post subject: 
the A-12 (the CIA version ) was hit several times. Tales are told of the planes coming back with shrapnel. I suppose tactics were modified, as far as I know NO SR-71s were ever lost to enemy action.

"We sleep safely in our beds because rough men stand ready in the night to visit violence on those who would harm us". George Orwell

Fighting For Justice With Brains Of Steel !
<img src="http://www.fas.org/man/dod-101/sys/ac/atengun2X.GIF" border=0>
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