Skunk Works Digest Tuesday, 7 March 1995 Volume 05 : Number 208a In this issue: Supersonic props Declassified Spy Images Re: Supersonic props Mach 1+ Prop. Ron Schweikert's SR-71 slides Offline for a time Ron's SR-71 pix Re: Ron's SR-71 pix X-33 More Flying Wing Re: X-33 Re: X-33 New "Blackbird" Patch Re: X-33 Ron's SR-71 slides screwed-up images (maybe) Re: X-33 Ron's address Article: Stealth Helicopter at Groom ABR and A-17 pix Groom Lake FTP archives at harbor? NOT! ---------------------------------------------------------------------- From: David Lednicer Date: Tue, 28 Feb 1995 11:32:39 -0800 (PST) Subject: Supersonic props Propellers with localized regions of supersonic flow are pretty common. Even if the prop tip isn't moving at a supersonic velocity, there can be local regions of flow where the air on the blade has been accelerated to supersonic velocities. Sometimes the shock created behind this region will "delocalize" to the far field. This is some of the wop-wop sound you hear as a Huey tries to fly fast. The Huey's rotor has a tip speed of 814 ft/sec at 100% Nr. This is M=.73 at Sea Level Standard conditions. Coupled with another M=.15 of forward flight speed (100 kt), there is likely a shock on a good chunk of the outboard blade. If you ever go to the Reno Air Races, listen (its hard not to) as the AT-6s thrash around the course. That awful noise you here is supersonic flow on the outer part of the prop producing shock waves. Now, a separate issue comes up when you want the forward flight speed of a prop driven aircraft to be supersonic. The angle of attack experienced by a propeller blade is that angle above and beyond the vector sum of the rotational velocity and the forward flight velocity. If you are flying really fast, the vector sum plus angle of attack will produce an angle approaching 90 degrees. Hence, the lift produced by the prop blade will be largely in the rotational direction. Resolving this lift into the thrust and torque directions will result in little thrust and lots of torque. Even worse, the blade's drag goes way up from the high helical velocities, and this now resolves into the negative thrust direction. Coupled together, this causes the prop's efficiency to fall through the floor, right when you need a lot of thrust to get through the airframe's drag rise that develops as you approach M=1.0. To get an idea of the blade angles involved here, find a picture of "Rare Bear" on the course at Reno. The blades will look like they are almost feathered, because of the high blade angles required to get any thrust. I believe that the F-84H had a prop that was called a supersonic prop only because a large part of the prop radius was moving at supersonic helical speeds. As far as I know, the airframe never got close to going supersonic. I think that they also relied on residual jet thrust from the turboprop to get a good part of their thrust at the top end. BTW - I examined the "Mach Buster" at Oshkosh in 1988 - it is (was) a scam. Lots of wishful thinking went into creating that deathtrap. ------------------------------------------------------------------- David Lednicer | "Applied Computational Fluid Dynamics" Analytical Methods, Inc. | email: dave@amiwest.com 2133 152nd Ave NE | tel: (206) 643-9090 Redmond, WA 98052 USA | fax: (206) 746-1299 ------------------------------ From: Rich Thomson Organization: Design Software Group, Evans & Sutherland Computer Corp. Date: Tue, 28 Feb 1995 15:03:37 -0700 Subject: Declassified Spy Images Unfortunately, none of them are of the Skunk Works, they all look like they are of various areas of Russia. However, I thought some of you skunkers would enjoy this. -- Rich ------- Forwarded Message Date: Tue, 28 Feb 1995 13:25:03 -0700 To: dsg_develop@pre.dsd.ES.COM From: Norman Angerhofer Reply: angerhof@dsd.ES.COM Subject: Spy photos Id: <199502282025.NAA23086@pre.dsd.ES.COM> -------- According the the NY Times, Clinton has de-classified 800,000 spy photos from 1960-1972. Check it out in your spare time :-) http://edcwww.cr.usgs.gov/dclass/dclass.html --Norman ------- End of Forwarded Message -- Between stimulus and response is the will to choose. ------------------------------------------------------------------ Rich Thomson Internet: rthomson@es.com Fractal Freak ------------------------------ From: Steve Mansfield Date: Wed, 1 Mar 1995 09:04:19 GMT Subject: Re: Supersonic props In your message dated Tuesday 28, February 1995 you wrote : >If you ever go to the Reno Air Races, listen (its hard not to) as >the AT-6s thrash around the course. That awful noise you here is supersonic >flow on the outer part of the prop producing shock waves. I can vouch for that. The two times I've been to Reno I've had pylon passes, which means that the gaggles of AT-6s passed just feet (it seemed like inches) over my head. After a race, I found myself shaking my head to get rid of the faint ringing. Much worse than the Unlimiteds (P-51s, Bearcats et al). _____________________________________________________ Steve Mansfield steve@syntax.demon.co.uk Syntax Editorial, London rotsky@cix.compulink.co.uk Tel: 0181-801 7363 CIS: 100124,3240 Mobile: 0850 667272 Fax: 0181-801 4957 ------------------------------ From: "RUSSELL.B" Date: 01 Mar 1995 07:56:07 GMT Subject: Mach 1+ Prop. Alright, I will ask the ignorant question (I am so very ignorant). What determines if a prop goes supersonic or not, other than the obvious diameter and rotation speed. I mean this question from the standpoint of design, ie. number of blades, angle of attack (varied with constant speed props), cord and taper of the blade and all those other things I was taught about while learning to fly (at very sub-mach numbers). And what is the status of turbo-fan testing? Several years ago I saw a Gulfstream that Locheed, NASA and GE had fitted with a turbofan for the starboard engine for test and evaluation. Just another software type question. Bob Russell Systems Programmer State of Georgia DOAS ------------------------------ From: czbb062 Date: Wed, 1 Mar 1995 10:36:18 -0600 (CST) Subject: 1 of Ron Schweikert's SR-71 slides If your mail system can handle that big a single e-mail, I can send you a 140KB .uue file which decodes to a 100KB .gif file. It is scanned for monitors set at 640x480 resolution. Michael Eisenstadt (czbb062@access.texas.gov) ------------------------------ From: ron@habu.stortek.com (Ron Schweikert) Date: Wed, 1 Mar 95 10:42:09 MST Subject: Offline for a time Hi gang. As many of you know, I'm going off-line for a time (hopefully a very short time). If you try to send me personal mail and it bounces, that's why. I'll get back in touch as soon as I get a permanent connection. Thanks for all your feedback on the SR pictures. Perhaps we can agree on two or three to have digitized and blown up, thus saving us some money? I should be on-line until Friday afternoon at this address. Take care! Ron ------------------------------ From: MiGEater1@aol.com Date: Wed, 1 Mar 1995 15:27:51 -0500 Subject: Ron's SR-71 pix Re: Ron's SR-71 slides. They are fantastic. They consist of shots that I unlike any I've seen published. I would heartily recomend a set of these treasures for anyone with more than a passing interest on the SR. Plus... The quality is excellent for dupes. Thanks again Ron, Checksix to all and to all a good night. John ------------------------------ From: czbb062 Date: Wed, 1 Mar 1995 18:45:20 -0600 (CST) Subject: Re: Ron's SR-71 pix On Wed, 1 Mar 1995, MiGEater1@aol.com wrote: >They are fantastic. They consist of shots that are unlike any I've seen >published. I would heartily recomend a set of these treasures for anyone >with more than a passing interest on the SR. Plus... The quality is excellent >for dupes. Indeed they are. I have 3 scanned for subscribers who would like to put them on their screens (at 640x480 resolution). parked1.gif SR-71 parked in front of hanger 100KB (140KB in uue format) parked2.gif different angle 215KB (300KB in uue format) runup.gif awesome shot of runup including pool of leaking fuel under plane 170KB (234KB in uue format) If your mailer can handle files this large, I can send 1 or more to you by e-mail and you can uudecode them back into binary with any uudecoder program (available for download from cica mirror ftp sites). I shall scan more of Ron's slides when time permits. Michael Eisenstadt (czbb062@access.texas.gov) ------------------------------ From: David Windle Date: Thu, 02 Mar 1995 14:59:07 Subject: X-33 Does anyone have any info on the aerospike engines that LADC will be using on their X-33 proposal ? I'd be very interested to hear any thoughts on the SSTO as a whole which will surely be a factor in the future success of Lockheed.I haven't started my homework on the subject and would appreciate your comments. So anyone want to talk X-33 ? Best wishes David ------------------------------ From: Christian Jacobsen Date: 2 Mar 1995 09:33:28 U Subject: More Flying Wing Subject: Time:9:25 AM OFFICE MEMO More Flying Wing Date:3/2/95 This outtake from the latest Journal of Electronic Defense (JED) fits some of the Flying Wing stories we have been hearing: New High-Altitude, Long-Endurance UAV Prototype to Roll Out This Month This month, Skysat Communications Network Corp. (New York, NY) plans to roll out a prototype of its Sub Space Platform (SSP), a new high-altitude, long- endurance UAV. The platform is designed for the commercial market, but has potential military applications as well. The 121-ft flying-wing design will be constructed from composite materials and developed in two versions -- conventionally powered and microwave powered. Both versions are expected to carry an 850-lb payload at altitudes up to 70,000 ft, according to Anthony Asterita, vice president of program development at the company. In addition, the microwave-powered version is expected to fly at these altitudes for up to six months per mission. The key to such long-endurance flights, said Asterita, is a device which converts microwave energy, beamed up from the ground, into DC power. The conventionally powered vehicle is expected to fly up to several days per mission. For payloads, the company is looking at a number of possibilities, covering applications such as communications and surveillance. Surveillance payloads may include radar and electro-optic or infrared sensors. Commercial applications include datalinks and countrywide cellular communications in countries with limited communications infrastructures. According to Astertia, military interest has focused on the conventionally powered system, with a detailed briefing about the SSP having already been presented to DOD officials. For the time being, the military will receive updates on the progress of SSP test flights. Those test flights are scheduled to begin in April and extend until a production version of the conventionally powered vehicle is released in 1996. The microwave-powered SSP is scheduled to debut in 1997. (Reprinted without permision) ------------------------------ From: larry@ichips.intel.com Date: Thu, 2 Mar 1995 10:20:20 -0800 Subject: Re: X-33 >Does anyone have any info on the aerospike engines that LADC >will be using on their X-33 proposal ? I'd be very interested to >hear any thoughts on the SSTO as a whole which will surely be >a factor in the future success of Lockheed.I haven't started my >homework on the subject and would appreciate your comments. >So anyone want to talk X-33 ? I'd love to talk X-33. The only think I can offer on linear aerospikes however, is a fascinating photograph of a real Rocketdyne linear rocket engine minus the aerospike nozzle. In a wonderful textbook on rocket engine design that Rocketdyne has fairly recently published through the AIAA, there is a black and white photo of this engine. The first photo of an actual linear rocket engine that I've ever seen. Has anyone ever seen another photo published of an actual linear engine before? It's VERY different looking of course, than your standard rocket engine. I imagine there are theoretical papers on aerospike nozzles available. Does anyone have any good references? Of course we have to realize here we are really talking about two things. The linear clustered rocket engine itself (pumps, feeds, injectors, chambers, etc) and the aerospike nozzle component. Larry ------------------------------ From: George Allegrezza 02-Mar-1995 1441 Date: Thu, 2 Mar 95 14:47:31 EST Subject: Re: X-33 If you'd like to see an artist's conception of a linear aerospike as applied to a smaller version of the Aeroballistic Rocket, see the RLV Program home page: http://rlv.msfc.nasa.gov/rlv_htmls/RLV1.html George George Allegrezza | Digital Equipment Corporation | "There is nothing more dangerous than Mobile Systems Business | a race fan with grading equipment." Littleton MA USA | allegrezza@ljsrv2.enet.dec.com | -- Humpy Wheeler ------------------------------ From: "JOE P." Date: Thu, 02 Mar 1995 14:31:27 -0400 (EDT) Subject: New "Blackbird" Patch I recently received a copy of the alumini edition of my old high school newspaper and what do I see but an article on the AFROTC unit inspection held recently at the school. This unit is appearently in its second year of operation and received very high marks in the inspection. What really caught my eye however was the picture of the patch this unit has adopted as it's unit patch. The picture was only in newspaper b&w so I can not tell you of the colors used but the picture centered on the patch is of a SR-71 or maybe its A series predecessor as if it were about to fly directly under you. The detail in the newspaper was not that clear but there were two rather noticable exhaust plumes coming from the engines. I presume that these were simply drawn in for art's sake since if an actual "secret penatration" aircraft were to have this heavy an exhaust trail, it sure wouldn't be a secret for long. Well with this little bit of info I guess I will turn the "Sealth" mode back on and go into lurking again. See my radar trac star to vani fr yo r sc.... ! Direct from the halls of Edinboro University - (814) 732-2484 and directly from the terminal of, - 142 Miller Bldg. - Edinboro Univ. Joe Pyrdek pyrdek@edinboro.edu - Edinboro PA 16444 ------------------------------ From: Mary Shafer Date: Thu, 2 Mar 1995 15:02:45 -0500 (EST) Subject: Re: X-33 We're going to fly an aerospike on the back of 844 next year. As soon as we finish these sonic boom flights, the plane's coming down for mods. 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.... ------------------------------ From: czbb062 Date: Thu, 2 Mar 1995 21:05:46 -0600 (CST) Subject: Ron's SR-71 slides The 3 scans I did were testing 1-2-3, provisional, low resolution (640-480) but good enough to distribute. I've sent out about 20 sets and on arriving home this evening I've got about 18 more. List-owner Dean! Please set up some space on skunk-works' server for Ron's images (and others hopefully). There is a very interesting nighttime view from somewhat above the action: a habu being set up under bright incandescent lights. Ron didn't have tungsten slide film with him so the colors are way off. I plan to scan it as a black and white image. -------------------------------------------------------------------------- Whiners corner: it is very tedious to send sets out as I have to quit and flush sent-mail in my /Mail directory every other send. Ron's set surely has 5+ keeper images which will make it impossible for me to distribute them personally once I get them satisfactorily scanned. --------------------------------------------------------------------------- BTW, what is the consensus of the list vis-a-vis resolution size and format? I might mention that the nasa.dryden image archive scans theirs to 1280x1020 in 24-bit .jpg format. These are around 350KB to download, but to see them your machine has to decompress them to the images' original size: 3.74MB! (1280x1020x3) and you would have to have a monitor capable of 1280x1020 and a 2MB video accelerator card to see the whole picture even in 256 colors. Some of you have requested 24-bit jpg's; what resolution size would you prefer? For those of you who want to shuffle through your favorite aircraft images on your monitor, gif format might be preferable because they don't need decompressing. Some of you probably download high rez jpg's and resize and reformat them to your taste; some are not that into computer images and are not sure they want to be. RFC As of now, I am unilaterally copping out of e-mailing anymore sets (except to the 18 or so pending requests). And besides, today's my birthday (verdad!). Michael Eisenstadt (czbb062@access.texas.gov) ------------------------------ From: czbb062 Date: Thu, 2 Mar 1995 22:39:58 -0600 (CST) Subject: screwed-up images (maybe) Hey gang! Sorry for all the bandwidth I'm wasting. I think the images I have been sending out this evening may have gotten corrupted. I saw blank lines in 2 of the uue files as they were being sent out and that won't work if they are really missing. Will check it out tomorrow. Dean? Archive space, please, please, please! Michael Eisenstadt (czbb062@access.texas.gov) ------------------------------ From: "Christian Jacobsen" Date: 3 Mar 1995 08:51:17 U Subject: Re: X-33 Subject: Time:8:43 AM OFFICE MEMO RE>>X-33 Date:3/3/95 I hope I am not the only one here.... I have no idea what an aerospike or a linear rocket engine is. Does someone want to post a description to bring everyone up to the same level of understanding? I (and I am sure some other lurkers) would appreciate it, - - Christian ------------------------------ From: "John T. Ewing" Date: Fri, 3 Mar 95 13:31:49 MST Subject: Ron's address Does anyone have Ron's snail mail address? I need to send him some $ for the slides. Did he get a new email address yet? JTE -- _____________________________________________________________________________ John T. Ewing | jewing@ishp2.az.honeywell.com Unix Systems Administrator | Honeywell Space and Aviation Systems | Commercial Flight Systems Group | Phoenix, Arizona ------------------------------ From: PsychoSpy@aol.com Date: Sat, 4 Mar 1995 12:49:04 -0500 Subject: Article: Stealth Helicopter at Groom Lake TITLE: EX-WORKER DESCRIBES STEALTH COPTER SUBTITLE: The Air Force has been testing the high-tech craft at Groom Lake, a former base employee contends. PUBLICATION: Las Vegas Review-Journal DATE: February 26, 1995 AUTHOR: Susan Greene A classified, black-budget stealth helicopter was being tested at the Groom Lake Air Force base as early as 1990, a former base employee said this week. The former worker, who asked not to be identified, closely monitored daily base operations and revealed the code name for the helicopter as "T.E.-K," standing for "Test and Evaluation Project K." That code name is consistent with those of at least two previous stealth projects tested at the classified Lincoln County air base -- the F-117 stealth fighter, known as "T.E.-A," and the B-2 stealth bomber, known as "T.E.-B." The former worker described the helicopter as drab green, angular and riveted, with gull-wing doors that flip vertically and cup underneath the body when closed. The two-seater was loaded with telemetry gear in back and flew silently, without the loud beating of rotor blades typical of other helicopters, he noted. The former worker said two of the helicopters were stored near the southern end of the base complex in Hanger 8, the structure where the Air Force reportedly stored the B-2 while testing that aircraft during the late 1980s. He recalled that pilots took the helicopter for spins up to twice a day, sometimes testing them against Soviet radar systems in the Nellis Air Force Range, and sometimes simply hovering over the air base, occasionally switching directions. "I'm not sure exactly what they were testing, but it looked like they were trying it out pretty completely," he said. Some aspects of his description match details about secret high- speed stealth helicopters outlined in the Feb. 6 issue of Aviation Week and Space Technology magazine. Aviation experts believe plans for such aircraft have been under way for at least 10 years. "This is a project that could be very close to completion," said John Pike, director of the Space Policy Project for the Washington-based Federation of American Scientists. Experts say light, quiet and stealthy helicopters could be used for clandestine "Rambo-type missions," quick-in, quick-out assignments without being noticed. "I'd say they could get a lot of use out of that type of aircraft," Pike said. Officials at the Pentagon and Nellis Air Force Base would not comment specifically on the existence of stealth helicopters or on other black-budget aircraft being tested within the Nellis Air Force Range. They have also refused to acknowledge the existence of the Groom Lake base itself, which has been observed by thousands of onlookers from nearby mountain ridges in Lincoln County. The Air Force has applied to withdraw those ridges as a buffer zone around the air base. That withdrawal is expected to be approved this spring. ### ------------------------------ From: George Allegrezza 07-Mar-1995 1029 Date: Tue, 7 Mar 95 10:40:18 EST Subject: ABR and A-17 pix For those of you who, like me, enjoy speculative artists renderings, check out the March 1995 issue of Final Frontier. There's a nice rendering of the Lockheed Skunk Works' proposed Aeroballistic Rocket SSTO vehicle on the cover. You can see the linear aerospike engine in very simplistic form. One of the tail surfaces carries the Skunk Works (tm) logo. Is it me, or does the ABR have strong similarities to the many variants of the Lockheed Star Clipper proposal of the 1960s, especially in terms of general configuration and capabilities? Also, the February 1995 issue of Air Forces Monthly has a small three-view line drawing of the "A-17" by Pete West, accompanying a story on the Boscome Down incident. This A-17 rendering doesn't show the swing wings, but does highlight the A-17's YF-23 heritage. George George Allegrezza | Digital Equipment Corporation | "There is nothing more dangerous than Mobile Systems Business | a race fan with grading equipment." Littleton MA USA | allegrezza@ljsrv2.enet.dec.com | -- Humpy Wheeler ------------------------------ From: Adrian Thurlow Date: Tue, 7 Mar 95 15:32:20 +0000 Subject: Groom Lake Hi skunkers, Last weekend I visited my local secondhand book store and purchased a small book called 'Warbirds Illustrated No. 24 - US Spyplanes'. It runs to 72 pages and covers U2, SR71 and relatives, B57, and EC135 types. There are some good shots. It also contains a satellite photo of Groom Lake. It claims it to be a NASA/Landsat image and goes on to state that the most ultra secret work has now been moved to two other facilities. The book was published in 1985. Has anyone any comments regarding the other facilities? Regards Adrian Thurlow Technology Integration / Det.4 9th SRW \ B48 Room 5 / \ BT Labs / _ \ Martlesham Heath ____(( ))_________/_/_\_\_________(( ))____ Ipswich \ \_/ / Suffolk U.K. Now only distant thunder Tel. +44 1473 644880 Fax. +44 1473 646534 e-mail. adrian.thurlow@bt-sys.bt.co.uk The views expressed above are not necessarily those of BT. ------------------------------ From: "Baughman, Steve" Date: 8 Mar 1995 13:24:07 -0700 Subject: FTP archives at harbor? NOT! Hello, Upon subscribing to this mailing list, I received a reply which stated: >An archive of past messages, plus some interesting GIF images and other info, >is kept on harbor.ecn.purdue.edu for anonymous ftp. Connect to Harbor, >give "anonymous" as the login, and your e-mail address as the password. >Then cd to /pub/skunk-works and look around. Unfortunately, it appears that the archives have moved or been deleted. sbaughmn@apple.com ------------------------------ End of Skunk Works Digest V5 #208a **********************************