Cv640 From United States of America, joined Aug 2000, 948 posts, RR: 6 Reply 3, posted (12 years 7 months 2 weeks 5 hours ago) and read 2608 times:
I jump seat home and to work often with Northwest and usually ride on the 757 and A320/A319. The 757 always seems to be at .80-.82, depending on whether they're running late or not. The Airbuses are always at .78.
Occasionally I have been on Fed Exs A300 and A310, they seem to be between .78-.80 all the time.
I have never been on a 717, but the Dc-9 cruises at .75and the MD80 between .76-.78.
As for the rest I'm not sure, one thing to remember is that an airline has the last say in cruise speed. The Mmo is the limiting factor, but most airlines, especially with the newere computer controlled aircraft, set the speed that is the best for economy, so who knows, what one airline uses can be diffrent for another.
Hope this helps
Greeneyes53787 From United States of America, joined Aug 2000, 844 posts, RR: 0 Reply 5, posted (12 years 7 months 1 week 6 days 21 hours ago) and read 2567 times:
Cruise speed and top speed are different. Some 747s, I understand, are capable of a thirsty .91 mach level flight with a moderate load. Further, I recall that their wings are swept back more than airbusses and other Boeings. The only commercial aircraft made in the USA with an equal wing sweep, I recall, are the Convair 990 and 880 at approximately 39 degrees.
The Boeing 720 was basically designed to be able to maintain .90 mach on the level. Their sweep was 35 degrees, the aircraft were light (lighter than the 990) and the thrust capability was high proportionately.
Qantas operated a pretty hot 707 that was light but fast. Others need to tell the qualifying specs here. I have them, but I think others enjoy posting them more than I do.
Skystar From Australia, joined Jan 2000, 1363 posts, RR: 3 Reply 10, posted (12 years 7 months 3 days 11 hours ago) and read 2448 times:
Ok, just to clear some of this up.
A319/320/321. Max M0.82. Econ: M0.78 (up to M0.79)
A330/340. Max M0.86. Econ: M0.82 (actually, it really is M0.805 from what I have been told).
747. Max M0.92. Econ M0.84-0.86 (depending on weight, some carriers will fly it on a standard M0.84 or an LRC schedule. Also dependent on cost index). Eg, heavy 744, init crz at FL310 at M0.86. Towards end of the flight, FL390, M0.84.