Xref: utzoo sci.aeronautics:98 sci.space:14422 sci.space.shuttle:3723 Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!uakari.primate.wisc.edu!ginosko!usc!venera.isi.edu!raveling From: raveling@isi.edu (Paul Raveling) Newsgroups: sci.aeronautics,sci.space,sci.space.shuttle Subject: Re: X-30, Space Station Strangles NASP Message-ID: <10022@venera.isi.edu> Date: 6 Oct 89 01:26:29 GMT References: <6430@quick.COM> <5292@eos.UUCP> <4983@omepd.UUCP> Sender: news@venera.isi.edu Reply-To: raveling@isi.edu (Paul Raveling) Organization: USC Information Sciences Institute Lines: 47 In article <6430@quick.COM>, srg@quick.COM (Spencer Garrett) writes: > > The Shuttle uses *two* glidepaths on final. They fly most of the > approach on a 17 degree (as I recall) glideslope, then make an > abrupt pitch up to the normal 3 degree glideslope. It looks > like the two intersect right off the end of the runway (where > "right off" may be a mile or two at these speeds) and they only > spend a few seconds (10 or 15?) on the 3 degree slope before > starting the flare. That's about right, but I'm not convinced there's really a 3-degree portion. The approach profile is just about like the X-15's speed-brakes-inadvertently-extended approach, where the flare was a 2G pullup ending essentially on the deck. The end of this approach went like this: Time Altitude Speed Event (sec) (ft MSL) (knots) ----- -------- ------- -------------------------------- 23 5,200 325 Roll out onto runway heading 18 3,900 325 Begin flare (2G pullout) ~10 ..... ... Lower flaps 8 ..... 275 Flare completed: Drop gear, jetisson ventral fin 0 2,200 180 Touchdown BTW, earlier I cited a 300 knot approach speed. That's for a normal approach and for the 1st 2/3 of this emergency approach; procedure for this one calls for accellerating to 325 knots when approaching the 90-degree key point, which in a rectangular pattern would be the middle of the base leg. Note the level flight deceleration -- 95 knots in 8 seconds, about 20 ft/sec**2, or 2/3 G. > Now for the questions! Is "coming feet dry" the same as extending > the landing gear? I think Mary was referring to the point where the shuttle crosses the coastline. ---------------- Paul Raveling Raveling@isi.edu