Friday, May 3, 2019

How is possible to shoot down a stealth fighter?

How is possible to shoot down a stealth fighter?
What is stealth? Stealth is a convergence of technologies which makes an aircraft electronically unobservable, primarily via Radar. The anti-radar technology is two-fold: the skin of the aircraft can be radar absorbent, but the main trick is to build the aircraft in a shape which scatters the radio energy away from the radar set which sent the signal. What is a fighter? A fighter is an aircraft that shoots down other aircraft. Fighters use guns, infrared guided missiles and radar guided missiles. Most modern radar guided missiles work by pointing the missile more or less in the target direction, illuminating the target with radar (from the jet, or from the missile itself; generally from the missile itself these days), and launching. The wavelength of the missile and jet radar is dictated by the physical size of the missile or jet. The main purpose of radar-resistant technology for a stealth fighter is avoiding being detected in the first place by enemy radar, but also defeating radar guided air to air missiles. Of course, what nobody will tell you: the air to air radar guided missiles haven’t historically been very effective. The US has some of the best ones; the AMRAAM. They’ve only shot down 9 aircraft in combat thus far using this weapon; it has a kill probability of around 50% depending on who you ask. Previous generations of such missiles (the AIM-4, AIM-7 and Phoenix) were fairly abysmal. The AIM-4 was a complete failure. The AIM-7, also a turkey in its early versions with a 10% kill probability in the Vietnam War (later versions were better). The Phoenix never managed a combat success, despite several attempts, though it was somehow considered a program success anyway, mostly by paper pushing war nerds. By and large, the venerable IR guided sidewinder works best. Amusingly, the Air Force thought the beyond visual range radar guided air to air missile would make stuff like guns and dogfighting obsolete … back in the 1950s. They were so confident in this, most of the Vietnam era fighters didn’t come equipped with guns. They were completely wrong . Yet, that is the justification for fielding the gold plated turd known as the F-35; a fighter so bad, it can’t even out fight a 45 year old design. The stealthy technology can’t really defeat IR missiles, which can now home in on a target which is merely warmer than the ambient air. All aircraft are warmer than the ambient air, even “stealthy” ones. Friction is one of the fundamental laws of physics. So, if a stealth fighter is located at all, by eyesight, ground observers or low frequency radars or whatever: an IR missile is a big danger. There is no immunity to gunfire, of course, so if you see a Stealth fighter with your eyeballs, and are close enough to draw a 6, you can shoot it down. Now, it’s worth thinking a bit about the fighter role. What good is an invisible fighter? There are a couple of issues with the concept, which has never actually been usefully deployed in combat anywhere in all of history. It is also rarely spoken of. If you want to shoot down other jets with your stealth fighter, you have to find them first. To find them, the best way to do it is using radar. Maybe you can do this with AWACS. AWACS somewhat assume air superiority has already been established. They’re big lumbering things everyone can see, both because they have giant signatures to radar, and because they are emitting radar signals. Maybe you can turn on your stealth fighter’s radar briefly, and hope the enemy’s electronic warfare facilities can’t see it, or hope the passive radar sensors work. Either way, you had better hope it is a fairly big country, and it is dark outside, or someone could find your stealth fighter. People did a reasonable job of spotting planes with binoculars and telephones back in the day. Modern jets are a little more than twice as fast as WW-2 planes, but that’s still plenty of time to alert air defences. Invisibility to radar guided missiles is only of partial utility;if you’re spotted, and your aircraft isn’t otherwise superior in air combat , you stand a decent chance of being shot down. So, for practical use as a fighter, stealthiness is only somewhat theoretically advantageous. It’s really the attack/bomber role where Stealthiness shines as a concept; mostly for taking out air defences on the ground. The F-117 (which was a misnamed stealth attack aircraft, an actual use for the technology) was shot down in the Serbian war by a Hungarian baker by the name of Zoltan Dani. The way he did it was as follows: first, he had working radars. He did this by only turning them on briefly, and moving them around a lot, to avoid wild-weasel bombing raids. He also used couriers and land line telephones instead of radio to communicate with the rest of his command structure; he basically had no radio signal which could have been observed by US attack aircraft. He also had “primitive” hand tuned low-frequency radars. Low frequency means long wavelength. Long wavelength means little energy is absorbed by the radar absorbent materials, and, more importantly, almost none of it is scattered away from the radar receiver. Since the wavelength of a low-frequency radar is comparable to the size of the aircraft itself, the fine detail which scatters away modern centimeter-wavelength radars doesn’t have much effect on meter-wavelength radar. Mr Dani shot his SA-3 missiles up, guided it in using a joystick, and that was the end of the F-117, a trophy part of which now hangs in the garage of a Hungarian baker in Serbia. Similarly, if you want to shoot down stealth fighters, you need an integrated air defense system which uses long wavelength radars to track targets, and you dispatch interceptors to shoot them down with IR missiles, guided in by the air defense radar. Which is exactly how the Soviet Mig-21 system worked. It worked pretty well in Vietnam. It would probably work well against F-35’s, which are not as maneuverable as Mig-21’s in a dogfight. #Gm*

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