Mutt,
In our performance manual, if the FRA is >1000' AGL, then the MFRA is the FRA for both ENG OUT and standard ALL ENG cases.
Why?
My guess (and its only that) is that at a field where the standard ENG OUT FRA @ 800' doesn't have you clear of an obstacle, the performance gurus iterate the calculation until they get a profile that does.
Obviously flying this profile ENG OUT will be the more limiting case, so its simple for them to say the new non-standard FRA applies in both cases.
Presumably, if having calculated the obstacle clearance profile, based on the reduced gradients and you still can't clear the obstacles, you're looking at an OCP.
What I'm not clear on is that normally the T/O profile ends at 1500'. In the case where this doesn't have you clear of an obstacle, segment 2 of the climb is extended until you find a FRA which does have you clear of this obstacle, but how far out do you extend your protected trapezoid in this case?
HTH.
Last edited by SR71; 19th Aug 2004 at 13:37.