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How not to design a Shuttle.
In article ,
Pat Flannery wrote: Fuel additives to reduce the radar delectability of the engine exhaust are also mentioned, this apparently did prove successful and was used operationally. Wasn't that boron added to the JP-9, or is my faulty memory at it again? -- Herb Schaltegger, B.S., J.D., GPG Key ID: BBF6FC1C "The loss of the American system of checks and balances is more of a security danger than any terrorist risk." -- Bruce Schneier http://dischordia.blogspot.com http://www.angryherb.net |
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Herb Schaltegger wrote: Wasn't that boron added to the JP-9, or is my faulty memory at it again? Boron was used in "Zip Fuel"; it upped fuel energy but generated a huge smoke cloud- probably not the best thing for stealth. In this case the additive was cesium. From the Oxcart history report I cited: "Lockheed's new entry was much like it's first, but with several modifications and a new designator, A-12. It too, would employ two of the powerful J58 engines. Lockheed's major innovation in reducing radar return was cesium additive in the fuel, which decreased the radar cross section of the afterburner plume. This improvement had been proposed by Edward Purcell of the Land committee." Pat |
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On Tue, 15 Mar 2005 14:56:50 -0600, Herb Schaltegger
wrote: Wasn't that boron added to the JP-9, or is my faulty memory at it again? ....IIRC, it was cesium. OM -- "No ******* ever won a war by dying for | http://www.io.com/~o_m his country. He won it by making the other | Sergeant-At-Arms poor dumb ******* die for his country." | Human O-Ring Society - General George S. Patton, Jr |
#4
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Pat Flannery wrote:
Herb Schaltegger wrote: Wasn't that boron added to the JP-9, or is my faulty memory at it again? Boron was used in "Zip Fuel"; it upped fuel energy but generated a huge smoke cloud- probably not the best thing for stealth. In this case the additive was cesium. From the Oxcart history report I cited: "Lockheed's new entry was much like it's first, but with several modifications and a new designator, A-12. It too, would employ two of the powerful J58 engines. Lockheed's major innovation in reducing radar return was cesium additive in the fuel, which decreased the radar cross section of the afterburner plume. This improvement had been proposed by Edward Purcell of the Land committee." Pat One of the P&W engineers I interviewed said that they tried running "zip" through a J-58. Not only did it gum up the afterburner injectors and the turbine (causing it to grind to a halt thirty seconds after cutting fuel), but it also left a half-mile trail of dead vegetation behind it. Nasty stuff. |
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Pat Flannery wrote:
Another interesting find were these photos of the Convair "Kingfish" RCS test mockup, showing that the leading edge triangular RAM inserts weren't unique to the Lockheed design: http://www.testpilot.ru/usa/convair/...h/kingfish.htm There are two fascinating aspects to these photos: 1. The RCS model looks too small to be a full size Kingfish mock-up. 2. The mock-up has no apparent canopy, making one wonder if this is either a reconnaissance drone or missile derivative of the Kingfish design. Was this the Convair competitor for the D-21? Pat Both Lockheed and Convair were getting advice from a team led by the late Frank Rodgers, so it's not surprising that they'd have similar RCS features. FISH also had the same serrated leading edges, which would have been filled with Pyroceram triangles. The only artifact I've seen of FISH is a sheet of stainless steel honeycomb with a notch cut out. It really is the full-size RCS model of KINGFISH. Some of the photos that are out don't really give the sense of scale. Also be aware that it's got its (flat) belly in the air in every photo. If you look closely, you can see a bubble for the canopy, but it's underneath and in shadow. |
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Paul A. Suhler wrote: One of the P&W engineers I interviewed said that they tried running "zip" through a J-58. Not only did it gum up the afterburner injectors and the turbine (causing it to grind to a halt thirty seconds after cutting fuel), but it also left a half-mile trail of dead vegetation behind it. The one I heard about is where they cranked up all six of the XB-70's engines with it, and pretty much generated as much smoke as a forest fire. Pat |
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Paul A. Suhler wrote: It really is the full-size RCS model of KINGFISH. Some of the photos that are out don't really give the sense of scale. Also be aware that it's got its (flat) belly in the air in every photo. Yeah, I figured that out fairly quickly after seeing the photos The A-12 was also mounted inverted on the RCS pylon. If you look closely, you can see a bubble for the canopy, but it's underneath and in shadow. Now that you point it out, I can see it. It's just blended in so well, that's it's hard to notice. Pat |
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Pat Flannery wrote:
http://www.testpilot.ru/usa/convair/...h/kingfish.htm 2. The mock-up has no apparent canopy, making one wonder if this is either a reconnaissance drone or missile derivative of the Kingfish design. Was this the Convair competitor for the D-21? Look at the drawings (which show a cockpit), and the second photograph (which is the only one which shows the whole aircraft). The cockpit is plainly present (though very small in relation to the size of the aircraft.) The remainder of the photographs show the *bottom* of the aircraft (the model was built 'upside down'), so of course the cockpit isn't visible. D. -- Touch-twice life. Eat. Drink. Laugh. -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
#9
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Peter Stickney wrote: I don't think they ever tried running installed engines on Zip. By doing that, you'd contaminate the entire fuel system - and given the characteristics of Zip fuel, you'd have to write it off before you could decontaminate it. By hte time they'd gotten around to final configuration selection for the B-70 and F-108 (Let alone the A-1 A-12), they'd given up on the idea of running it through the rotating parts. There was still some interest in using it to fuel the afterburners, but weighing the disadvantages - Toxic Byproducts, Smoke, separate fuel systems, and all that jazz, the slight increase in range wasn't worth it. I misremembered a quote by J93 project manager Paul L. Dawson in which he said "Boron chemical fuel or HEF was only considered for use in the afterburner section and some tests were actually run using it. Aside from the problems with borate deposits on the nozzle and afterburner section areas, the plume of exhaust smoke would have rendered the use of this "zip' fuel impractical, especially during takeoff. It was truly awesome even from one engine, and the thought of six engines running this way boggles the imagination. I'm sure it would have created a cloud that would have persisted for days. The environmentalists would have had a field day, even in that era of just awakening concern for the impact on the Earth." However, an aircraft once did fly using zip fuel: on September 28th, 1958, a specially modified J79-powered F-101 (normally the Voodoo used twin J57s) flew using zip fuel in its afterburner sections. It would be fun to find some in-flight photos of that aircraft with the smoke generators operating. With twin boron-boosted J79s that would be one hot Voodoo- you'd have around 3,300 pounds extra thrust to play with while having an engine installation that was over 3000 pounds lighter. Pat |
#10
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Derek Lyons wrote: Pat Flannery wrote: http://www.testpilot.ru/usa/convair/...h/kingfish.htm 2. The mock-up has no apparent canopy, making one wonder if this is either a reconnaissance drone or missile derivative of the Kingfish design. Was this the Convair competitor for the D-21? Look at the drawings (which show a cockpit), and the second photograph (which is the only one which shows the whole aircraft). The cockpit is plainly present (though very small in relation to the size of the aircraft.) Yeah, I could see it when I looked closer, it's just very blended in. Look at this shot though: http://www.testpilot.ru/usa/convair/...ingfish_06.jpg Assuming the guy on the ladder who's at the back edge of the wing is 5' 5" inches tall, then the wingspan is around 5.75 to 6 times his height- which means a wingspan of around 30 to 35 feet. But wingspan is supposed to be around 55 feet, so is this a half sized model? The other oddball thing is that this is apparently supposed to be used for RCS cross section tests, but the metalwork on it looks really crude- note the bad seams on the nose, and the crack in the underbelly on this photo: http://www.testpilot.ru/usa/convair/...ingfish_02.jpg You stick this in front of a radar, and it's going to be echoing all over the place. Lockheed's A-12 RCS test specimen was like a piece of chromed sculpture compared to this thing The remainder of the photographs show the *bottom* of the aircraft (the model was built 'upside down'), so of course the cockpit isn't visible. I knew is was upside down from the location of the vertical fins, which otherwise might have interfered with landing. ;-) Pat |
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