wolit@alice.UUCP (Jan Wolitzky) (01/04/85)
>> However, it would seem to me that, unless the X-29's >> control systems are effectively shielded, >> merely a nearby detonation of a nuclear missile not >> even intended for it would cripple the plane via >> the EMP (electro-magnetic pulse) effect. > a) EMP is easy to shield against in a small, self-contained piece of > circuitry (as opposed to a power grid with hundreds of miles of > exposed wire acting as antennas). > b) EMP only occurs in a sea-surface burst or an air-space interface burst, > not with any random airburst. Well, the X-29 is NOT a "small, self-contained piece of circuitry", nor is its electronics. The fly-by-wire control system, of necessity, extends throughout the aircraft. Additional EMP softness derives from the presence of many radar, communication, and navigation antennae. Objection (b) should hardly be comforting to X-29 backers: it's a whole lot easier to detonate a few nukes in the ionosphere and thereby blanket an entire theatre, for example, than it would be if you had to target each plane separately! -- Jan Wolitzky, AT&T Bell Laboratories, Murray Hill, NJ; (201) 582-2998
jlg@lanl.ARPA (01/08/85)
> Well, the X-29 is NOT a "small, self-contained piece of circuitry", > nor is its electronics. The fly-by-wire control system, of necessity, > extends throughout the aircraft. Additional EMP softness derives from > the presence of many radar, communication, and navigation antennae. In terms of EMP, a single aircraft (even a 747) is NOT an extended target. An extended target is something that is (say) half a mile across, made of conducting materials, and using electronics which are sensitive to transients (the bigger the collecting surface, the larger the transients will be so that even pretty stable components can be effected if they are hooked to a power grid or something). Of course, radio and radar equipment have to be especially hardened since their function is to detect and amplify small radio frequency signals. I'm not fully aware of work being done in this area, but I wouldn't be suprised to discover that such devices could be made to survive. ------------------------------------------------------------------------------ The greatest derangement of the mind is to believe in something because one wishes it to be so - Louis Pasteur James Giles
dsmith@hplabsc.UUCP (David Smith) (01/09/85)
So why is the X-29 any worse than the F-16? The F-16 uses a force stick to electronically signal desired control surface movements. (Actually, it's a little fancier than that. I read that horizontal stick force does not signal aileron deflection, but roll rate.) And if a hydraulically actuated B-52 lost its electronics to EMP, how would it navigate home? I don't know how susceptible our planes are to EMP, but the Air Force does test them for it.