From: skunk-works-digest-owner@mail.orst.edu To: skunk-works-digest@mail.orst.edu Subject: Skunk Works Digest V5 #191 Reply-To: skunk-works-digest@mail.orst.edu Errors-To: skunk-works-digest-owner@mail.orst.edu Precedence: bulk Skunk Works Digest Friday, 27 January 1995 Volume 05 : Number 191 In this issue: Re: TR-3A Re: Planes of the Right Stuff A shock wave question active noise cancellation external combustion Re: Planes of the Right Stuff Congressional heat on Air Force re Groom Lake The Right Stuff Xplanes... Re: Planes of the Right Stuff Re: Two different craft? Re: Lauda Air 767 NF-104 and the latest Grob skunker Re: TR-3A TR-3A Whoosh sound Re: Fuel dumping and the SR Turing Clarification? Active noise cancelling -- true cancelling, or covering up? Re: Planes of the Right Stuff Re: New birds ? See the end of the digest for information on subscribing to the skunk-works or skunk-works-digest mailing lists and on how to retrieve back issues. ---------------------------------------------------------------------- From: "J. Pharabod" Date: Fri, 27 Jan 95 15:31:22 MET Subject: Re: TR-3A >>"The craft seemed to be at about 2,000 feet but it is hard to estimate >>distances at night. All the while no sound was heard until it was directly >>above us. It slowed and paused in mid-air for a second and emitted a real >>low but audible rumble which seemed to come on instantaneous, as if someone >>said "OK, turn on the sound". >That to me sounds like someone seeing an aircraft TURING, which would >both explain it seeming to "pause" briefly from certain viewing angles, >AND a increase in engine noise if the exhaust were to suddenly be aimed >in your direction. >Dean Adams (Fri, 27 Jan 1995 05:25:18 -0800) Dean Adams is right, anybody who (like me) lives near a big civilian airport can attest that. But I see also from time to time "weird pulsed contrails" (maybe not as sharp as on the photo once reproduced in AW&ST, but with the same regular spacing between the "knots") which are not ... Aurora ! J. Pharabod ------------------------------ From: Kathryn & Andreas Gehrs-Pahl Date: Fri, 27 Jan 1995 10:33:31 -0500 (EST) Subject: Re: Planes of the Right Stuff I forgot to explicitly write, that all three F-104A-10-LO aircraft were redesignated NF-104A-10-LO after the modifications. These included not only the Rocketdyne AR-2 rocket engine (military designation LR121-NA-1, where the LR stands for Liquid-fueled Rocket), installed in an 8.5 degree upward angle and the reaction control system in nose and wingtips, (which used H2O2), but also enlarged wings and the F-104G (bigger) tail and modified air-intake spikes for a better high-altitude performance. An explosion in the H2O2 system damaged one of them, but the damage was repairable. The training program was delayed by the crash, the explosion, and other problems until August 1965. The movie made it look like Yeager decided to take the nice shiny Starfighter out for a spin and crashed and burned. If this would have been true, I doubt that he would have made General. In fact, Col. Charles 'Chuck' Yeager was at the time the commander of the Aerospace Research Pilots School (now USAF Test Pilot School), and the flight was an attempted high-altitude record flight, involving all sorts of planning and performance monitoring. - -- Andreas - --- --- Andreas & Kathryn Gehrs-Pahl Absolute Software 313 West Court St. #305 schnars@umcc.ais.org Flint, MI 48502-1239 Tel: (810) 238-8469 - --- --- ------------------------------ From: ron@habu.stortek.com (Ron Schweikert) Date: Fri, 27 Jan 95 09:03:38 MST Subject: A shock wave question Regarding the unstarts -- >Ron Schweikert responds: >>I'll defer the "full" answer to experts, And you guys have. Thanks! Larry now says: >Well, how about a jet engine nut! Okay, you asked for it! :-) Your posting was excellent and I appreciate it, but I need more, MORE! :-) If I can ask the right questions, maybe you can clear out some cobwebs of dusty memory and enlighten me on areas I never fully understood. When an aircraft hits M1, the shock wave is "at right angles to the flow." But where precisely IS the shock wave? I've seen some pictures on tv that seem to show it at the center of pressure on a wing (i.e. NOT on the leading edge), while others seem to show the shockwave attached to the leading edge. I've apparently missed something here, or could it be different based upon the type of wing? As it regards the SR, when it hits M1, is the shock wave forming and attached on the tip of the spike, or towards the back of the spike where the restriction inside the inlet is? (I know there's several shock waves, but I refer to the shock wave the engine is dealing with). Also, if the wave is at right angles to the flow, and the flow seems to be following the spike, and therefore up at an angle (and down on the bottom), does this mean the wave is actually leaning "forward?" Also, what happens to the flow as speed increases? I'd always believed it "bends" back until it's in the nacelle, but does the speed increase change the flow, and therefore the way the shock wave works? (See, you opened a can of worms--now I want answers!!! :-) :-) I tried to draw a side view of the spike and nacelle, but it doesn't work well here. Let me describe it. The spike stays full forward as everyone sees it until M1.4. If you look in the inlet of an SR you see that the spike keeps its same shape until about 4 inches inside the inlet where it then flattens out (and btw has a lot of open slots in it to let air *inside* the spike, maybe boundary air flow control?). Anyway, the spike then quickly angles down the opposite way as it leads to the engine until it's about 12 inches in diameter. The main constriction leaves just about 4" of clearance between the surface of the spike and the nacelle. About 22" inside the nacelle is the shock trap, a 5/8" opening in the inner part of the nacelle where the engine is housed. Okay: at 1.4 the shock wave is in the inlet (assuming it was attached to the tip, and not formed at the constriction where the shock trap is ?????). As the speed increases, the spike moves back further into the nacelle for the expressed purpose of holding the shock wave at the right point. To me this implies the wave formed at the shock trap at the beginning by design. Could it be we're talking two waves here? One built at the constriction inside the engine, and one outside that attaches to the spike? Moving the spike backwards towards the engine though implies to me that the wave in question is in fact attached to the tip of the spike and is bending in. Well, actually if that's the case and the wave bends more with speed, it'd seem the wave is wanting to move farther towards the engine, so the spike if anything would have to move FORWARD to keep it in one spot. But since the spike moves back, this lends credence to the idea of the wave being formed at the constriction. Ah...ignorance! Anyway, that's a lot of questions, but I hope I've asked the right ones. Technical discussions via email is tough! Again Larry, your posting was excellent, it just raised more questions about the angle/position of the wave. Thanks in advance for more insights!! Ron ------------------------------ From: "Thomas A. Gauldin" Date: Fri, 27 Jan 1995 11:33:26 -0500 (EST) Subject: active noise cancellation In some recent posts, mention was made of the reported "triangular craft" giving out a "whooshing" sound. The comment made was like someone said, "Ok, lets turn on the sound." Assuming that they were correct in their observation, doesn't this sound a lot like active noise cancellatin? If it was, the comment would have been, "Ok, turn off the speakers." If the present technology of jet engine design "raises" the average sound of the engine, making it easier to muffle, wouldn't it also lend itself better to active cancellation? Large (presumably flat) surfaces reported on the triangular craft would also lend themselves to using the skin as a speaker "cone" with high powered transducers attached. Thomas A. Gauldin Here's to the land of the longleaf pine, Raleigh, NC The summerland where the sun doth shine, BSRB45A on Prodigy Where the weak grow strong and the strong grow great, FAX (919) 676-1404 Here's to Downhome, the Old North State. ------------------------------ From: "Thomas A. Gauldin" Date: Fri, 27 Jan 1995 11:39:58 -0500 (EST) Subject: external combustion The thread dealing with shock waves and the inlet spike on the SR-71 reminds me of the comments of the "doughnuts-on-a-rope" reported sighting. Couldn't the shock wave created by the nose of a hypersonic plane be used as the "forward" end of an external combustion pulse jet engine? Using the same techniqe to drop the speed to subsonic levels for the SR-71 engine, a subsonic stream of air could be induced into the void following the shock wave. I wonder if this might work in a ram jet type of engine? Thomas A. Gauldin Here's to the land of the longleaf pine, Raleigh, NC The summerland where the sun doth shine, BSRB45A on Prodigy Where the weak grow strong and the strong grow great, FAX (919) 676-1404 Here's to Downhome, the Old North State. ------------------------------ From: Geoff.Miller@EBay.Sun.COM (Geoff Miller) Date: Fri, 27 Jan 1995 09:43:52 +0800 Subject: Re: Planes of the Right Stuff > These included not only the Rocketdyne AR-2 rocket engine (military > designation LR121-NA-1, where the LR stands for Liquid-fueled Rocket), > installed in an 8.5 degree upward angle [...] What was the purpose of angling the rocket engine upward? Did that compensate for its being mounted above the airframe's longitudinal axis or something? - --Geoff ------------------------------ From: ConsLaw@aol.com Date: Fri, 27 Jan 1995 12:49:54 -0500 Subject: Congressional heat on Air Force re Groom Lake I just received a personal phone call from Douglas Roach, a staff member of the Congressional National Security Comittee. The impression I received from the phone call is that some members of Congress are becoming interested in what happens at Groom Lake. The NSC is blaming the Air Force for what even Mr. Roach claims is excessive secrecy. Mr. Roach told me that he has been to Groom Lake. He and the staff director visited the base last january and urged them (the Air Force) not to keep it a special access facility. He said that he spent 27 years testing aircraft, and he is the one who makes recommendations to members of Congress concerning test evaluation facilities. Regarding the toxic waste allegations: he said that the Air Force told him that it did not take over the facilities until the 50s. Before that it was in the hands of the CIA. The Air Force states that since it has had Groom, all state and local environmental laws have been upheld. If you wish to contact Mr. Roach, here is his address and phone number Douglas Roach National Security Committee 2120 Rayburn Washington DC 20515 (202) 225-0883 I urge every participant of this board to send a letter expressing your opinion to your Representative. Here's the path my latest letter took. About a month ago, I sent a letter to Representative Stephen Buyer, an Indiana representative who has a closed Air Force Base (Grissom) in his district. The letter discussed the public disclosures about the expansion of Groom Lake air base (essentially the material from Popular Science March 1994), as well as discussing Jonathan Turley's toxic exposure cases. Representative Buyer is a Gulf War veteran who himself has suffered from toxic exposure. Representative Buyer forwarded the letter to my congressman, Representative Andy Jacobs, Jr. (Earlier, I sent two letters to Mr. Jacobs directly. He sent me back a personal reply that he had heard of Groom Lake, but just spoke in generalities that he is opposed to all government waste, military and non-military.) This time, Representative Jacobs forwarded my letter - apparently with an indication of concern to Floyd spence, Chairman of the National Security Committee. Apparently Floyd Spence told staffer Douglas Roach to call me. I could be wrong, but I sensed some fear in his voice. He wanted to convey a "just trust us" message. At the same time, he was discussing how he thought Air Force secrecy was out-of-hand. Not a very convincing argument. The bottom line is that if you write enough letters to enough people, you just might make an impact. So go to it! Steve Hofer - Indianapolis Conslaw@aol.com ------------------------------ From: Corey Lawson Date: Fri, 27 Jan 1995 10:39:37 -0800 (PST) Subject: The Right Stuff Xplanes... They used miniatures. - -Corey Lawson csl@booster.u.washington.edu ------------------------------ From: Kathryn & Andreas Gehrs-Pahl Date: Fri, 27 Jan 1995 14:35:40 -0500 (EST) Subject: Re: Planes of the Right Stuff Geoff wondered why the rocket engine of the NF-104As were pointing upwards. I don't know for sure, but I suppose the reason was that the thrust- vector of the rocket engine (its longitudinal axis) was going right through the center of gravity (or center of lift ?) of the aircraft. Please correct me if I am wrong (just guessing :) ). - -- Andreas - --- --- Andreas & Kathryn Gehrs-Pahl Absolute Software 313 West Court St. #305 schnars@umcc.ais.org Flint, MI 48502-1239 Tel: (810) 238-8469 - --- --- ------------------------------ From: lumber@hopf.dnai.com (Jack-Lee Gibbons) Date: Fri, 27 Jan 1995 12:10:12 -0800 Subject: Re: Two different craft? > I disagree strongly. Not that I'm an expert, but given the hypothesized >mission of the TR-3, it would be a substantial asset to be able to hover. >Since the TR-3 is supposed to supply real-time reconnaissance, specifically >to stealth attack craft and presumably to other aircraft, being able to >loiter unobserved would be a considerable advantage. I just can't see any advantage to this. You are assuming that this aircraft is completely invisible but as far as I know, there is no aircraft that is completely invisible. As Dean Adams pointed out, a hovering aircraft would have nozzles pointed downward, thereby making HUGE IR signature. I'd hate to be hovering when someone fired a shoulder launched heat-seeker at me! Not to mention, even the F117 has a radar signature. It is very small but it is there. The fact that it is moving help to keep it hidden but if it were to stop, it could be either triangulated by the gap in coverage or by a search radar locking onto the area and narrowing it's search coverage. This can't really be done with a fast moving jet, at least not effectively enough for fire control. > I also must take exception to "you can take as good a picture at >mach3 as you can hovering". I don't know of any craft that can >fly mach 3 on the deck, and pictures taken from 25,000m cannot >have near the quality of pictures taken from 5,000m or less. This is not true. Military satellites can take pictures from orbit with reported resolutions down to .5 meters. I have even heard descriptions like "We can look at a guy sitting in a park reading a newspaper and tell you what the headline says.". I don't think that a reconaissance aircraft can take better pictures than that. As for speed, the SR-71 took some extremely high detailed pictures when it was really moving. As >well, pictures taken from 5,000m or less while traveling at mach >3 would likely be substantially inferior to pictures taken while >hovering. This also assumes that one "takes pictures" -- real-time >video links showing "the big picture" to attack aircraft on the >deck would be even more useful. We use drones for "real time" reconaissance data links. They are expendable, secure, and usually go undetected. As far as I know, fighter aircraft don't have the capability or need to receive real time pictures of the battle area. That is what AWACS and JSTARS are for. They can receive data from reconaissance and satellite images, interpret them and send strike and routing data to the navigation and weapons computers on the proper aircraft. > This may sound a little silly, but it would also be useful for >pilots to have a fair idea of when they can be observed or heard >by persons on the ground. For all of the wonderful radars in the >world, the MK I ear and eyeball are still among the most acute and >sensitive detectors. Understanding the practical limitations against >detection by eyeball and ear, even those belonging to unwary civilians >rather than alert enemy trooops, would likely help TR-3 pilots avoid >doing anything foolishly observable in more hostile circumstances. This type of testing could just as well be carried out by military personel on the ground. There is no reason to overfly civilian residences and endager them with testing that could be done on a military reservation. "I've done it over and over.. You see, I kill breeders." "God is dead." -Nietzche "Nietzche is dead." -God Lumber ------------------------------ From: John Regus Date: Fri, 27 Jan 1995 09:51:25 -0500 (CST) Subject: Re: Lauda Air 767 Boeing did finally confirm the thrust reversers had a problem and issued a notice to airlines on how to fix the problem. It will be interesting to see what comes of the US Air investigation. John F. Regus | (713) 960-0045 | SYS/370/390 SYSTEM SOFTWARE ENGINEERING WUI:REGUSHOU | On Fri, 27 Jan 1995, George Allegrezza 27-Jan-1995 0803 wrote: > This is a bit off-charter, but was this the 767 where the thrust reversers > deployed in flight? As I remember, Lauda claimed this was the cause of the > crash and Boeing claimed it was impossible. Boeing later did numerous > simulations trying to reproduce the hypothetical reverser deployment. > Don't know if it was ever resolved to anyone's satisfaction. Niki's > a pretty tenacious guy, though, and I expect he stayed in Boeing's face > until he got a direct answer. > > Amplifications and corrections (perhaps off-list) invited. > > George > > George Allegrezza | > Digital Equipment Corporation | "Dumber than advertised." > Mobile Systems Business | > Littleton MA USA | -- Dot Warner > allegrezza@tnpubs.enet.dec.com | > ------------------------------ From: Emory Tate Date: Fri, 27 Jan 1995 16:20:12 -0500 Subject: NF-104 and the latest Grob skunker Thanks for the detailed info on both the Grobs and the NF-104, Andreas. The one you asked about disposition on, 0756, may be the donor for the NF-104 engines which I understood Mitch Clapp to say were going to be used in BLACK FOAL as the POC engines (or perhaps he just meant NF-104-class engines? - I gather that OTS means really OTS, so they might really be the old NF-104 hardware). Trying to respond to your request for more interest in the Grob thread, "News Breaks" in the 23 Jan AvLeak has a great photo of the 185ft (!) wingspan Grob Strato-2C. Powered by 2 (?) 3-stage supercharged TC IO-550, with 400shp each driving 20ft-dia pusher 5blade props. Claimed duration with 4 aboard in shirtsleeves is 8h at 80Kft, 48h at 60Kft, and 80hr at 40Kft! Cruise is 107kt at 1800lb payload. Development was funded by the German Ministry of Research & Technology. Of note is the size (check out the tiny guys at each in-hangar wing support) and the fact that there's NO apparent wing droop, despite an aspect ratio of about a gazillion-to-one. It does have a big-ass vertical fin, no doubt to cope with what must be hellacious adverse yaw in a turn (put the stick in the opposite direction you want to go, perhaps?). Regards, Emory ------------------------------ From: larry@ichips.intel.com Date: Fri, 27 Jan 1995 13:42:05 -0800 Subject: Re: TR-3A >BTW, speaking of the TR-3A, am I the only one wondering if >"Air International", et al have borrowed some writers from the >Enquirer or something? :) To be speaking so matter-of-factly, >about something we have yet to get *any* hard facts yet seems\ >a little strange to me. I AGREE!! I have mentioned my curiosity over this Dr. Baker guy myself! Since Rene Francillon is the U.S. Editor for Air International, when I talked to Rene I figured he might know something about this guy. So I asked him. Rene didn't know ANYTHING about him at all! I asked about Dr. Baker's background - Rene knew nothing. I asked if the name 'Baker' was an alias - Rene knew nothing. Rene agreed much of what Baker wrote seemed to be speculation. This is not to say that some of what Baker writes might be true, but I agree it seems to be presented not as speculation, or even new information, but as past history or something, or as you said, very matter-of-factly. It would help if they explained who this guy is! Larry ------------------------------ From: MiGEater1@aol.com Date: Fri, 27 Jan 1995 17:16:24 -0500 Subject: TR-3A Whoosh sound Hi all, I saw a show on the Discovery channel a coulple of nights ago that profiled a silent car. They describe a system that uses sound wave 180 degrees out of phase with the original sound to create "anti-noise". The system was installed on the exhaust system of a luxury car. It used a microphone, signal processor, an amplifier, and a set of speakers ported out to an identical exhaust pipe as the original. The two pipes were mounted side by side. The car had no muffler but engine exhaust noise was rendered inaudible. I know there are a number of projects under development for the use of this technology in commercial aircraft. With enough power to enough speakers, you could mask even the roar from a gas turbine engine. The remaining majority of sound would be from the airflow around the surfaces of the aircraft. I imagine it would sound something like a "Whoosh" as described by the TR-3A observers. Just thought I'd add another strand to this thread. John ------------------------------ From: MiGEater1@aol.com Date: Fri, 27 Jan 1995 17:16:23 -0500 Subject: Re: Fuel dumping and the SR Hi Skunkers, been lurking for a while but thought I'd throw in a token bit of info into the ring. I caught the public display or SR-71 # 976 at Oshkosh in '89. When the engines were run up to full speed, just before takeoff, fuel started to dump out of the boat tail. After the aircraft was rolling and the burners ignited, fuel was POURING out at a rate of many gallons a second. I got some good shots of this. I did not ignite even thought it was just a few feet from the afterburner flame. I saw an F-15 do a touch and go and the very similar ball of flame appear just before zone V was reached on the takeoff roll. I spoke to the pilot during the air show (Quonset State '92) and askd him what happened. He stated something like: *An uncontrolled amount of fuel had been dump into the burner section* (a hiccup is what the he called it). Too much fuel, not enough oxygen therefore no ignition. Once the fuel hit the air after it left the exhaust nozzle, the fuel-air ratio returned to a point where ignition could occur. The result: a short duration ball of flame. Made sense to me then. Any comments from propulsion experts? John "I disclaim everything" ------------------------------ From: Christian Jacobsen Date: 27 Jan 1995 10:09:27 U Subject: Turing Clarification? Subject: Time:10:03 AM OFFICE MEMO Turing Clarification? Date:1/27/95 >That to me sounds like someone seeing an aircraft TURING, which would >both explain it seeming to "pause" briefly from certain viewing angles... Pardon my ignorance, but what is "Turing"? The only Turing I know developed a test for determining intelligence.... ;-) Thanks, - - Christian ------------------------------ From: ron@habu.stortek.com (Ron Schweikert) Date: Fri, 27 Jan 95 16:18:52 MST Subject: Active noise cancelling -- true cancelling, or covering up? >Hi all, > >I saw a show on the Discovery channel a coulple of nights ago that profiled a >silent car. They describe a system that uses sound wave 180 degrees out of >phase with the original sound to create "anti-noise". The system was >installed on the exhaust system of a luxury car. It used a microphone, >signal processor, an amplifier, and a set of speakers ported out to an >identical exhaust pipe as the original. The two pipes were mounted side by >side. The car had no muffler but engine exhaust noise was rendered >inaudible. > > I know there are a number of projects under development for the use of this >technology in commercial aircraft. With enough power to enough speakers, you >could mask even the roar from a gas turbine engine. The remaining majority >of sound would be from the airflow around the surfaces of the aircraft. I >>imagine it would sound something like a "Whoosh" as described by the TR-3A >observers. > >Just thought I'd add another strand to this thread. > >John > Hmm, think we could make a set for politicians? Actually noise cancelling has intrigued me ever since I saw the technology first demonstrated for aircraft headsets. There's so many places that it could be put to use, but I'm curious. I know high-frequency noise (or any for that matter) can damage hearing. If we were say in a shop where the noise output was high (say from machinery) and there were devices that output sounds in opposite phase, and therefore "cancelling" the original noise, how does that affect the ear? Aren't the vibrations that affect the inner ear (and therefore damage it) still present? Is the noise really "cancelled" or just "masked?" Does that make sense? (Aren't you guys tired of software-types asking these ridiculous questions? ) Ron ------------------------------ From: John1082@aol.com Date: Fri, 27 Jan 1995 20:20:21 -0500 Subject: Re: Planes of the Right Stuff There is a -104 on display at a city park in Burbank, california. It's up om a pole and I seem to remember a non-standard tail configuration which may have been the booster engine. But I have been mistaken before... ------------------------------ From: Mary Shafer Date: Fri, 27 Jan 1995 23:25:09 -0500 (EST) Subject: Re: New birds ? Er--I find the following so distasteful that I've vacillated for about 20 minutes about even typing it, but "jig", sort for "jigaboo", was (and, in some circles, I'm sure, still is) a nasty, vile word used to refer to people of sub-Saharan African descent. The only thing is, the use of the same word to refer to aircraft tooling stopped before people became particularly sensitive to such usages (I believe that the term Negro was still in use when the aerospace term was changed, which will give you all an idea just how long ago all this was). On the other hand, it's more pleasant to report that a "titch" is just a little bit--a pinch, a very short distance, an itty bit. As in "Oh, I'll just have a titch more dessert" or ""Move the left corner up a titch and it'll be level". Regards, Mary Mary Shafer DoD #0362 KotFR shafer@ursa-major.spdcc.com URL http://www.dfrc.nasa.gov/People/Shafer/mary.html Some days it don't come easy/And some days it don't come hard Some days it don't come at all/And these are the days that never end.... ------------------------------ End of Skunk Works Digest V5 #191 ********************************* To subscribe to skunk-works-digest, send the command: subscribe skunk-works-digest in the body of a message to "majordomo@mail.orst.edu". If you want to subscribe something other than the account the mail is coming from, such as a local redistribution list, then append that address to the "subscribe" command; for example, to subscribe "local-skunk-works": subscribe skunk-works-digest local-skunk-works@your.domain.net To unsubscribe, send mail to the same address, with the command: unsubscribe skunk-works-digest in the body. 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