Originally Posted by
Rainboe
We have a difference between planning and actual. We fly 120 minutes ETOPs which is calculated on a TAS of 399kts. It is a legal limit in line with actual capability. If one was to actually have a failure, I would not increase speed to this level, although fuel is loaded to do it. I think most pilots would proceed at a sedate speed nursing the remaining engine!
I think such reasoning is shared, once the engine has demonstrated to run on MCT/CON indefinitely in a shop, there's no point re-taking the test when airborne over high seas. Same applies for 1 hr take-off alternate case, where the planning limit is also based at approximately 400 kt TAS (737/320).
I think it quite possible that some highly powered types with engine out, and no large trim drag, will be more efficient as the engine is more efficent at high power. I think this applies more to highly powered business jets which probably have a very high single engine cruise. I've heard the Nimrod can shut down engines on loiter to increase endurance, so it is more efficient with an engine out.
Obviously, the closer the engine is mounted to the lateral axis, the smaller thrust-line displacement needs to be trimmed-out. The 767/757 data comes as a surprise, however.