A few interesting comments arise in the last 3 posts, starting with the venerable
John_T
My comment "
you could push the thrust to the Rated Limit in use with safety", lead to John's comments of "hmmm, OK, but do it carefully" (or words to that effect)
I agree entirely, from the certification and legal point of view, you could push up the thrust in a Reduced Thrust takeoff to the Rated Thrust in use, but.....Vmcg
IS a risky area not to be fiddled with. As I alluded to in an earlier post on this forum, I prefer (and so does my company) to leave the reduced thrust as it is, enjoy the improved controllability, in the acceptance that, from a performance point of view, aircraft performance without increasing thrust should be quite satisfactory.
alf5071h, in his usual "spot on" style has quoted wise regulatory words. Readers beware that the first quote relates to Reduced Thrust (not De-Rated Thrust) and is NOT a limit. Alf's third paragraph then goes on to say that De-Rated Thrust IS a limit. Spot on Alf, but readers beware of the oft confused difference between Reduced Thrust and De-Rated Thrust.
galaxy flyer, I'm totally in agreement, the "padding" that we enjoy in so many other performance areas is simply not there with Vmcg. True, Nosewheel steering inop is considered for the Vmcg certification, and you
MIGHT have NWS available to you to significantly assist with directional control problems. I say
MIGHT because on many aircraft types, NWS is programmed to become progressively reduced in authority as speed increases, up to the point with some aircraft where it is TOTALLY unavailable at V1 speeds. That "padding" is now gone, there is an unfavourable cross-wind not accounted for in certification, and you're in big trouble.
One of the frequent contributors on this forum (I dare not name him as he values his anonymity as I do mine) has had significant exposure to Vmcg testing on a certain airline aircraft. Try to get him wound up if you can, his tales of imminent aircraft losses in Vmcg tests are truly frightening. As
galaxy flyer points out, the test pilots knew it was coming, the shagged out pilot at his duty limits may not cope so well.
To end with a personal anecdote, by coincidence I operated a short sector yesterday on a low weight B777 using TO-1 and Assumed Temperature 60°C, a VERY low thrust setting. The F/O flew the sector, and, with this forum's wise words still in my mind, added to the briefing "If an engine fails at V1 don't even think about increasing the thrust". A very "switched on" guy he was, fully accepting and understanding the rationale behind my briefing. Maybe he's a Prooner too?
How many lives / incidents / accidents has PPrune saved? I suspect many, PPrune in my opinion has significantly contributed to aviation safety, and continues to do so. And Prooners, take it easy on the occasional total jerk who disturbs rational comment on these forums with "way-out" and crazy ideas. We learn something from them too!
We learn what
NOT to do when operating valuable aircraft with even more valuable human lives on board.
Best Regards,
Old (and getting older) Smokey