Taken from Boeing's Aero no 7:
New regulation 14 CFR 121.646 requires that all airplanes flown in extended operations must carry an ETOPS fuel reserve suffcioent to allow flight to an ETOPS alternate airport in the event of these three scenarios:- A rapid loss of cabin pressure at the most critical point followed by descent to a safe altitude as defined by oxygen availability
- A rapid loss of cabin pressure and a simultaneous engine failure at the most critical point followed by descent to a safe altitude as defined by oxygen availability
- An engine failure at at the most critical point and descent to OEI cruise altitude and diversion at OEI cruise speed
To me it seems scenario "b" is always the limiting one, but I am not ETOPS trained. Can you give an example where either "a" or "c" require more fuel?
FD (the un-real)