Each aircraft may well have a different low altitude max speed...this will
be given in knots of Indicated Airspeed (IAS)...and typically is about
350-400 knots for passenger aircraft. At low altitude, IAS and True Airspeed
(TAS) are pretty much the same. While the low altitude max speed is
expressed in knots IAS, the high altitude max speed is expressed as a Mach
number. Passenger jet max mach numbers vary from around .8M to close to .9M.

At high altitude, IAS and TAS often are quite different, with TAS being the
larger value.

The low altitude max speed limitation is an airframe limit and not a drag
limit. In most cases, the jet could go faster but for various aerodynamic
reasons, is restricted from doing so.
"Roger Helbig" wrote in message
news:40ccdcd9@hughey...
Airline or Military transport pilots .. I would like to ask you some
questions about the maximum speed that an airliner like a B-767 or 757 can
travel at low altitude. Someone claims that the speed at altitude is much
higher than that at low altitude because the drag of the wide body limits
the maximum speed at low altitude. Can any of you comment on that?

Thank you.

Roger Helbig



-----=osted via Newsfeeds.Com, Uncensored Usenet News =---
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----= Over 100,000 Newsgroups - 19 Different Servers! =---