From: skunk-works-digest-owner@mail.orst.edu To: skunk-works-digest@mail.orst.edu Subject: Skunk Works Digest V5 #51 Reply-To: skunk-works-digest@mail.orst.edu Errors-To: skunk-works-digest-owner@mail.orst.edu Precedence: bulk Skunk Works Digest Friday, 1 April 1994 Volume 05 : Number 051 In this issue: F-117 vertical stabilizers. Re: Multiple Sonic Booms Ti/Al alloys RE: Skunk Works Digest V5 #50 Re: Skunk Works Digest V5 #50 Talk about stealth! 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: tpoole@psi.wilmer.com (Poole, Timothy) Date: Thu, 31 Mar 94 08:29:20 EST Subject: F-117 vertical stabilizers. I also recall an article mentioning the fact that the inward canted fins, having to be mounted toward the outer edge of the plane, did not have the structural strength the designers were looking for. By having the fins canted outward, they could both be mounted on the center structural member of the aircraft, providing more strength. ------------------------------ From: Paul Michael Keller Date: Thu, 31 Mar 1994 09:00:16 -0500 Subject: Re: Multiple Sonic Booms Phil Verdieck shaped the electrons to say: >I may be wrong, but that 1 boom/mach sounds like a pure load. There >is at least one instance of multiple sonic booms that I know of, the >shuttle. I've been told that due to its design, when reentering it >double booms. One boom originating from the nose, and one from the >wingtips. I've been waiting for some of the aerodynamicists on the list to answer this, but if they're silent I'll speak up (their critique of this is welcome, I am an engineer, but not into aero). In general, any aircraft breaking mach 1 will always produce at least a double sonic boom, and maybe more, depending on it's airframe design. Here's how: From Paul Tipler's _Physics_, a college elementry physics textbook: <---Direction of Flight / / / / / __ / /_____/ | <_________| Date: Thu, 31 Mar 94 09:31:08 EST Subject: Ti/Al alloys I haven't submitted anything to this group for a while, been making the world go for my employer, work is the curse of the drinking class..... A few things have caught my eye in the last few months that may or may not interest this crowd: One of the factors that make a hypersonic A/C viable are materials that can stand up to the environment. This was covered in a seminar I attended at Oshkosh last year where I first heard of Titanium Aluminide alloys. The subject was brought back to mind by an article in the March 1994 issue of NASA Tech Briefs page 78 titled 'Thin CVD Coating Protects Titanium Aluminide Alloys'. The gist of the article is that using three Ti/Al alloys two coatings, a 10 micron Al/SiB, a 40 micron 'commercial coating' were tested against uncoated material. The results indicate that there is substantial reduction in weight gain, oxidation, with the commercial coating and even farther reduction with the Al/SiB coating. The tests were, static conditions at 1,000 degrees C and simulated hypersonic flight conditions at 982 degrees C for as long as 5 hours. From the graph, the presented results, it appears that the uncoated sample gained just under 3 mg/sq cm and the coated surfaces were under 1/2 mg/sq cm. From the March 1994 issue of Air International: - Speedbird, Concord, is 25 years old on March 2, - An article on page 133 details a vectored thrust F-16 called the Vectored Viper. Words of description fail... From the February 1994 issue of Air International: page 96 in an article pertaining to the reorganization of USAF: "The most recent alteration to the ACC structure involved the three KC-135Q squadrons being transferred to AMC in exchange for the theater airlift C-130s." I thought that the Qs were in the boneyard, and where did 3 squadrons come from? As far as I know there were only 15 ever built.. Sam ------------------------------ From: russellk@BIX.com Date: Thu, 31 Mar 1994 10:24:15 -0500 (EST) Subject: RE: Skunk Works Digest V5 #50 RE: Pope AFB crash Here's a mildly interesting sidelight on the tragic F-16/C-130 crash at Pope AFB. By way of disclaimer, this is all fourth-hand information, so if something is wrong, I apologize but that's the breaks. My wife, who works in a medical research lab, was talking to the head of Nuclear Medicine at Yale the other day. It seems that his son was at the controls, in the right-hand seat of the C-130 at the time of the accident. As I heard it, the impact jerked the wheel (yoke?) right out of the man's hands. His instructor, sitting in the lefthand seat, is reported to have said "Being hit by an F-16 is *not* a normal part of our training process. I'll take over from here." The Herc did a low-level flyby for the tower to assess damage (most of the tail was gone) and then landed successfully. ===================================== Russell Kay, Byte, russellk@BIX.com 603-924-2591 ===================================== ------------------------------ From: "Art Hackett, RM:1076, #:3-8585" Date: Thu, 31 Mar 1994 10:46:17 CDT Subject: Re: Skunk Works Digest V5 #50 An F-16C crashed and burned at Truax field in Madison, Wisconsin. It was a Wisconsin ANG plane. The pilot was on a routine training mission when an engine trouble light came on. He was making what seemed to be a routine landing when the tail hook failed to engage a snag cable. He bailed out as the plan was coasting down the runway suffering a broken back and misc other injuries. He's in good condition at a Madison Hospital. There are some reports that the plane was already on fire when the pilot ejected. The plane went of f the runway and exploded. ------------------------------ From: larry@ichips.intel.com Date: Thu, 31 Mar 1994 11:58:10 -0800 Subject: Talk about stealth! A summary from the 3/23/1994 Aerospace Daily: Names: RADIANT OAK, RADIANT IVORY, TALON SHIELD Navy's RADIANT OAK exercise validates satellite-to-shooter idea. Navy planes used information beamed directly from satellites to attack a moving target patrol boat off Southern California, validating the off-board "sensor-to-shooter" concept. The exercise was called RADIANT OAK and was conducted on Aug. 19, 1993. The exercise involved transmission of satellite data directly to the cockpits of an EA-6B and a P-3, both of which fired missiles from below the radar horizon of the target. A HARM missile fired by the EA-6B homed on and knocked out the target acquisition and target tracking radars on the target vessel, and a HARPOON missile launched by the P-3 penetrated the 100-foot-long craft's hull just above the waterline. The Navy has described the test in some detail (see below), but it has not identified the sensor that provided the target information. Gen. Charles Horner, commander in chief of North American Aerospace Defense Command, U.S. Space Command and Air Force Space Command, in a volume of testimony originally prepared for delivery to a CLOSED session of the Senate Appropriations Committee, and released by them this month, that RADIANT OAK is one of SEVERAL initiatives "to put space-originated information directly into the hands of the warfighters." The EA-6B from electronic warfare squadron VAQ-209, that led the air wing strike group on the RADIANT OAK excersize, had a fully integrated Multi-Mission Airborne Tactical Terminal (MATT) added to its basic avionics package. The off-board data to strike the patrol boat target was sent from the sensor via the near-real-time TADIXS-B and Tactical Related Applications broadcasts which were received with Tactical Receive Equipment (TRE). The data was filtered and displayed with MATT. The strike group flew a 500-mile, low-level ingress to the target area remaining terrain masked from the threat. They were guided to the target solely by off-board targeting data. The EA-6B crew derived the HARM 'range known' targeting solution from the over-the-horizon contact data provided. After the EA-6B fired its HARM, a P-3 from patrol squadron VP-60 used the TRE to launch a 'range and bearing' HARPOON missile from beyond line of sight to the target - without tracking data from the P-3's radar. Both missiles were successfully launched from below the radar horizon, enhancing strike aircraft survivability and ensuring the element of surprise. The HARPOON acquired, tracked and struck the target, piercing a three-foot diameter hole directly through the patrol craft two feet above the waterline. Integration of "this off-board, over-the-horizon adjunct will support a MULTITUDE of missions/warfare areas throughout the tactical air community," Nees wrote. Horner, in his statement, said several OTHER efforts are underway by U.S. Space Command to put real-time satellite information into the hands of warfighters. In the area of defense against attack by theater ballistic missiles, he said, the Navy is pursuing RADIANT IVORY, which uses data from Defense Support Program (DSP) early warning satellites "in combination with a national sensor." The Air Force's TALON SHIELD effort, he said, capitalizes on RADIANT IVORY and "will use MULTIPLE national and DSP sensors to increase the situational awareness-thereby improving both the probability of detection and the accuracy of missile launch parameters." ------------------------------ End of Skunk Works Digest V5 #51 ******************************** 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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