SR-71: Power by Chevrolet, Rubber by Goodrich

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Last week I visited the Pima Air Museum and thought that I would post some pictures of one of my favorite aircraft. Any ideas what these devices on the underside of the engine nacelle are for? I assume that they are to bleed off static charges. -Jeff
 
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In the Garage...
Interesting. I have very limited knowledge about how these engines work, but if it needs a separate engine to start, what if it suffers a casualty where the engine shuts off and it can be restarted. Is it possible?
 

Astro14

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Originally, it was twin Buick Wildcat engines. The jet first flew in 1964...before the big block was made, so that start cart was a later addition... While not BITOG focused, the Astro-inertial navigation system used an automated determination of known star positions (identified by spectral characteristics) to navigate at 2,000 MPH, far outside the range of radio navigation, decades before the first GPS satellite was launched. An automated version of a sextant, complete with azimuth, elevation, and object identification. That was incredible technology, and one of many incredible achievements of the jet.. Engines can be started in flight because they are windmilling already from the airflow through them...kind of like rolling a car down a hill, letting out the clutch and starting the engine without using the starter.
 
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Few years back took my nephew to the National Museum of the United States Air Force, @ Wright-Patterson AFB in Dayton. in the Museum Proper, the planes are of course off limits to touch. they're museum pieces. They also have a couple Hangers over on the main base, that you can visit (until they raise the funds to expand the museum itself) one with retired Presidential aircraft(Air Force 1's) you can go through, and an R&D Gallery. filled with various prototypes and "Test" craft. these, they let you get up close an even touch (at least back then). among that collection is the the sole YF-12 (Air Force Version of the CIA's A-12 oxcart, served as "prototype" for the SR-71) that still exists. http://en.wikipedia.org/wiki/Lockheed_YF-12 http://en.wikipedia.org/wiki/Lockheed_A-12 http://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird http://en.wikipedia.org/wiki/National_Museum_of_the_United_States_Air_Force
 
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Originally Posted By: ls1mike
Interesting. I have very limited knowledge about how these engines work, but if it needs a separate engine to start, what if it suffers a casualty where the engine shuts off and it can be restarted. Is it possible?
If it had a "flame out" in flight it used the air flowing through the engine and a very reactive chemical called "TEB" to restart the engine. The F-16 is also dependant on a start cart but it uses air from the cart to start the engine, not a direct coupling. Emergency power is provided by a small generator that runs on hydrazine like a rocket engine.
 

Astro14

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Originally Posted By: earlyre
Few years back took my nephew to the National Museum of the United States Air Force, @ Wright-Patterson AFB in Dayton. in the Museum Proper, the planes are of course off limits to touch. they're museum pieces. They also have a couple Hangers over on the main base, that you can visit (until they raise the funds to expand the museum itself) one with retired Presidential aircraft(Air Force 1's) you can go through, and an R&D Gallery. filled with various prototypes and "Test" craft. these, they let you get up close an even touch (at least back then). among that collection is the the sole YF-12 (Air Force Version of the CIA's A-12 oxcart, served as "prototype" for the SR-71) that still exists. http://en.wikipedia.org/wiki/Lockheed_YF-12 http://en.wikipedia.org/wiki/Lockheed_A-12 http://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird http://en.wikipedia.org/wiki/National_Museum_of_the_United_States_Air_Force
Not to get too pedantic - but the YF-12 wasn't a prototype for the SR-71, it was a modified A-12 that was designed to compete for the USAF's Mach-3 fighter requirement. North American was developing the F-108 Rapier, using the same YJ-93 engine as the XB-70 bomber. That's why the YF-12 doesn't have a chined nose section - it has a radome to house the fighter radar...which, incidentally, was being developed by Hughes. The AN/ASG-18 radar was built to support the very long range AIM-47 missile...and when the YF-12 project was canceled, that radar set was modified for the F-111B program (the Navy's F-111 fighter), where it was then called the AWG-9 and the missile was modified to the AIM-54...which, as every good fighter guy knows, became the core weapon system on F-14 when the F-111B, too, was canceled... http://en.wikipedia.org/wiki/North_American_XF-108_Rapier
 
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Originally Posted By: Astro14
Not to get too pedantic - but the YF-12 wasn't a prototype for the SR-71, it was a modified A-12 that was designed to compete for the USAF's Mach-3 fighter requirement.
that would be why I put "prototype" in Quotation marks. I know that wasn't really it's purpose. but i stand corrected anyway.
 

Astro14

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Then I apologize earlyre...I should have read it that way....still, the requirement for a Mach 3 fighter fascinates me...the tremendous design, metallurgy, systems and operational challenges proved too costly...particularly as guided missiles became capable of fulfilling some of the defense missions that the interceptor would have fulfilled.
 
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The SR-71 "Blackbird" is my favourite aircraft of all time. I was lucky enough to see one up close at the Hill Aerospace Museum in Utah when I was working for the 2002 Olympics.
 

Astro14

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Like you guys, I love the jet...and I suppose that I could keep track of which Blackbirds I've seen... The San Diego Air & Space Museum has an actual A-12 (single seat CIA variant) out front, next to the Sea Dart. The one on the USS Intrepid is an A-12 also. The Seattle Museum of Flight has an M-21 variant (rare, built to carry the D-21 drone). USAF Museum of Armaments (which has some really cool stuff, by the way) has a "big tail" variant mounted out front. The Udvar-Hazy center has one highlighted in the center of the museum. The Richmond, VA museum (I forget the name...it's right at the airport) has a Blackbird next to a Tomcat out front (and it makes my old jet look fat and slow by comparison). SAC Museum in Omaha has a Blackbird mounted at a dramatic angle in the entrance. The Kalamazoo "Air Zoo" has one. The Imperial War Museum in Duxford has one (though, I can't remember why or how they got it...but since we have an AVRO Vulcan in the SAC Museum, I guess we can share...). I am starting to sound like a train spotter...but seeing the YF-12 at the USAF Museum in Dayton, OH remains on my bucket list...
 
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Ontario, Canada
Originally Posted By: tom slick
If you find yourself in Palmdale (1hr North of Los Angeles) you could visit Blackbird Park. It's just outside of Air Force Plant 42 which is home to Skunkworks and other aircraft facilities.
Awesome!!! thumbsup
 
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Tacoma, WA
Originally Posted By: SnPb
Any ideas what these devices on the underside of the engine nacelle are for? I assume that they are to bleed off static charges.
The grille-like areas and doors on the nacelle help control bleed air flows. The goal is to maintain proper positioning of the inlet spike shockwave so the airflow in the duct is not choked off. The nacelles are key to the SR-71's performance. Jet engines take in air at about Mach 0.4 regardless of flight speed. Efficient operation of the inlet requires that it delivers the air to the engine at that speed. At SR-71 cruising speed the slowing down of the air to about Mach 0.4 is controlled by the intake shock cone and the shape of the downstream internal ducting. U.S. Patent 3,344,606 "Recover bleed air turbojet" describes how this is accomplished.
 
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Yes-the first 'start cart' engines were Buick nailheads. The Minnesota air guard museum had a Y-12 until CIA Langley wanted it more-
 
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Originally Posted By: Lapham3
Yes-the first 'start cart' engines were Buick nailheads. The Minnesota air guard museum had a Y-12 until CIA Langley wanted it more-
I thought they were Buick Wildcat's? BTW, this plane is the epitome of engineering. Absolutely incredible the developments and breakthroughs that happened during its creation. By far my favourite aircraft of all time. smile
 
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Flatlands of Indiana
Originally Posted By: OVERKILL
Originally Posted By: Lapham3
Yes-the first 'start cart' engines were Buick nailheads. The Minnesota air guard museum had a Y-12 until CIA Langley wanted it more-
I thought they were Buick Wildcat's? BTW, this plane is the epitome of engineering. Absolutely incredible the developments and breakthroughs that happened during its creation. By far my favourite aircraft of all time. smile
I recall reading several years ago that the original start carts used Big Buick V8s. Some 401 and 425 Nailheads were called Wildcats. The numbers after the Wildcat, for example Wildcat 445 was the foot pounds of torque the engine produced.
 
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