Originally Posted by
aterpster
president:
True, but irrelevant to performance and engineering. The starting point for computation of the takeoff flight path is an engine failure just above decision speed.
Also, good planning requires a contingency if the engine fails airborne and early into a SID. How do you switch to the preplanned OEI track? Sometimes, that path quickly disappears in mountainous areas. Thus, the reason the U.S. carriers got the FAA to permit the carriers to use a pre-approved carrier-developed departure path instead of using the canned SID. This option is generally limited to airports with challenging terrain.
I haven't been suggesting to follow an SID with an engine loss at V1. In fact this discussion wasn't even about engine out performance. What I did say was that with OEI you should be on an approved EFP... OR in some cases continue the SID IF you can make the required gradients. If not you obviously don't.