From: skunk-works-digest-owner@mail.orst.edu To: skunk-works-digest@mail.orst.edu Subject: Skunk Works Digest V5 #415 Reply-To: skunk-works-digest@mail.orst.edu Errors-To: skunk-works-digest-owner@mail.orst.edu Precedence: bulk Skunk Works Digest Sunday, 10 September 1995 Volume 05 : Number 415 In this issue: Re: Tier II Plus 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: Charles_E._Smith.wbst200@xerox.com Date: Sat, 9 Sep 1995 07:33:00 PDT Subject: Re: Tier II Plus All vehicles moving through air produce some type of turbulence. This turbulence causes emmisions in the 53GHz (ish) range. Compression and shock waves create fairly large disturbances relative to the background emmisions caused by the normal convective turbulence in the atmosphere. About "Stealth". There is no way to completely mask an aircraft from radar. What you try to do with stealth is to reduce the intensity of the return. By doing so the aircraft can travel closer to the antenna without being detected. Ground radar SOP until very recently was to set up a line of radar systems side by side with overlapping fan-shaped sweeps. The idea behind stealth was to limit the detection range such that the A/C could sneak in between the areas between the "fans". With the proliferation of cheap, mobile radar systems, this is no longer feasible. Also, its just a heck of a lot cheaper and quicker to put the Weasels up and keep the radars shut down. The Weasel is so simple- its pure beauty. Turn your radar on an it gets destroyed, leave it off and its just as useless! (See Dessert Storm for details.) The AF used to tell Congress the 117 was undetectable. Now they admit it has the radar sig of a "small bird". The only problem with that- is that not too many small birds fly at M 0.6 @ 30K ft. Stealth is kind of weird, really. I guess its the "winglets" of the 90`s. Remember when the Pentagon decided bombers should go M2? There`s always a new fad. From a design standpoint, there are some stealthy things that do work. The twin tails on the A10 mask the IR sig from the classic rear-quad pursuit of an IR-guided weapon. The V-tail on the 117 covers the exhausts from lookdown systems. (The TE jet exhausts) With the big push for steerable nozzles at present, the idea of IR supression has gone by the wayside for fighter/air sup. design (so I`m told, I haven`t designed any F`s lately!- or ever!!) In any event, it will be interesting to see what comes along next. Chuck Smith "Aerospace Engineer to the Stars" ------------------------------ End of Skunk Works Digest V5 #415 ********************************* 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. Administrative requests, problems, and other non-list mail can be sent to either "skunk-works-digest-owner@mail.orst.edu" or, if you don't like to type a lot, "prm@mail.orst.edu A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace all instances of "skunk-works-digest" in the commands above with "skunk-works". Back issues are available for anonymous FTP from mail.orst.edu, in /pub/skunk-works/digest/vNN.nMMM (where "NN" is the volume number, and "MMM" is the issue number).