Irrelevant indeed
Trimotor wrote:
"I don't agree that CI is effectively irrelevant and we might as well fly at 0.84M. Yes, we might land sooner, having used pretty much the same fuel, but the extra wear n the engine is NOT negligible (excuse the double neagtive). Anyone with any knowledge of the hot end problems appearing on the GE 90-115 will appreciate that. Just talk to the engineers."
I'm talking about facts, not guessing. You can take it for granted from a Mechanical Engineer with PG on Aircraft Design graduate: you land 6-7 min earlier on a 7 hours sector, burn the same amount of fuel, and yes, engine wear is negligible. Do it yourself: establish on a typical FL and weight at M.83,take note of every single engine parameter, accelerate to M.84, wait for stabilization (not less than 5 min) and take the same notes. Compare. You wont notice a difference.
Assumed temp takeoffs is a completely different thing, and of course, impact on engine life is definitive.
Sometimes I think this bean counters and so called "engineering or perfomance analysis" departments are prone in going on some nit picking issues completely displaced from the real life only to justify their existence on the payroll...they would be much more useful with more involvement with the hands on people, the pilots.
Last edited by fullforward; 29th May 2008 at 15:34.