You can't really talk about CASM as that is very airline specific. It depends on the costs (C) of the rest of the organisation, the number of seats in the aircraft (S) and the sort of routes they fly, so the number of miles (M). That is why for example both Easyjet and British Airways both operate the A320 family, but their CASM is vastly different.
For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and ther
Aeroweanie From United States of America, joined Dec 2004, 1612 posts, RR: 51
Reply 4, posted (6 years 1 month 2 days 21 hours ago) and read 2853 times:
Quoting billreid (Thread starter): The MD-11 was an aircraft that did not live up to specifications. When was this discovered and when did sales drop because of this.
During design, the engine manufacturers supply to the airframe manufacturer "engine decks" which are computer programs that simulate the performance of their engine. The decks supply fuel flow, thrust, etc. for a given power setting. The decks are for uninstalled performance, so they must be corrected for installation effects. Also the decks are typically optimistic. Most manufacturers audit the decks and reduce the optimism, based upon experience.
On the MD11, McD had a very limited development budget, so they didn't audit the engine decks. When they got to flight test, they discovered that the fuel flows were higher than had been predicted for given flight conditions. A big aerodynamic improvement effort was embarked on and the airframe drag was reduced. At the same time, the engine manufacturers tweaked their engines and got slightly better performance out of them. Despite this, the aircraft didn't live up to the original design guarantees.