Date: 29 Nov 97 03:24:32 From: "Michael F. Lechnar" <firstname.lastname@example.org> Organization: nams References: 1 2 3 4 5
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James Matthew Weber wrote: > On 21 Nov 97 01:59:53 , "Bart & Sylvia Peters" <email@example.com> wrote: > > >>BTW, can someone post "normal" cruising altitudes and speeds for the > >>main types used today? > > > >For a Boeing 747-400 initial cruise altitude at max t/o weight ( most of the > >time ex- far-east ) is FL 310 mach 0.85 depending on actual wind at the > >time. > >After Delhi a climb to FL 350 and mach 0.86 are possible. > > I don't believe this. > > Cruise on a 747-400 at these mach numbers carries a huge fuel burn > penalty. There is now ay the aircraft would make a Europe-Asia trip at > those speeds. Long Haul Cruise on a 747-400 is M.82, while M.86 may be > possible, I have never seen anyone do it. Nope, Long range cruise Mach, LRC, for the Pratt & GE 747-400s is between .85 and .86 Mach. Rolls is a touch slower. The only reason you would be at .82 Mach is to fly max range cruise at lower weights or for ATC. I have seen Mach .86 a lot. Mike Lechnar Aircraft Performance Engineer "If I was speaking for Boeing, I wouldn't be doing it here."