Approach thrust settings allow for rapid engine acceleration to GA thrust ---SOP ususally have a minimum altitude for having the engines spooled...in readiness-it's not a good idea in general to be at idle setting so low down
Concur. This is why I have issues with the criteria speeds for each class of aircraft for the final approach segment.
the designer's assumption is evaluated for the worst case it seems-as would be good enginering practice anyway
Exactly. in design, if you take the worst case for the missed, the airport alt, highest temp for that airport, max weight, all the bleeds, etc...you use this CG for the EO missed. In my experience, for a twin, this is less than 2.5%. For RNP, this means doing obstacle surveys for the MA corridor.
As you can see, there is little the P77 survey does for the missed..the OCS is 2.5%, so if your climb is at 2.5%, you have no ROC.
I can't see how TERPS and FAR 25 /121 can be so diverged?
Good comment! When you look through and try to design procedures to meet all of the applicable rules, you find many conflicts. The FAA exempts themselves on the rules when designing procedures, but unless you are able to dig into the 8260 forms, you dont know what they have exempted.