Posted: 6/30/2007 11:22:35 PM EDT
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Not talking top speed here but cruising speed, the speed when the plane is loaded for a mission. Looking at many planes data on the interweb, my previous guess that fighters are subsonic with cruise speeds the same as airliners seems to be correct. Cruise speed is dictated by the speed of sound, transonics and by fuel burn and the need to conserve fuel. Speed costs fuel burn, how fast do you want to go? There is one other factor, if a plane needs to stay low to avoid radar then there is the bumpy sky problem. Many days a plane will be beat up by the bumpy air, this is bad for airframe life, for the pylons and stores, the avionics and the pilot. Planes with high wing loading and/or very swept wings would do better at higher speeds and low altitude than those with light wing loadings and little sweep. On the other hand, if modern fighters were flown in a clean configuration, at 40,000 + ft and if burner was used to get supersonic then military power might keep the plane supersonic for some distance...but that's not the configuration they are flown in and being painted by radar is not a good idea. Nope, fighters look like .84 planes at 30,000 + and more like .7's Mach at very low altitudes and when going close to a fuel limited distance. The F-22 would be a major exception. Is that pretty much the way it is or do I have it wrong? PS One other thing, a B1 looks pretty good for fast low altitude. It has a lower surface to volume ratio than something like a Mig 29, it has lots of sweep, a fairly high wing loading, etc. The B1 looks like it could run fighters out of gas if they were vectored toward it and the B1 crew knew about it and sprinted. It also looks like it might be able to beat them up and their stores on a bumpy day. A fighter isn't going very far at high speed and very low altitude on internal fuel. Of course the fighter could go higher but it might lose the B1 in the ground clutter too. The B1 has it's own problem with getting beat up by the air. It is long and that makes it vulnerable to bending in the up and down plane. But it has small canards to reduce the bending moment. My babble aside, how is it in real life? |