you basically cut a good margin
May I emphasise that, as a pilot and performance engineer, I have absolutely no problem using derate plus ATM plus overspeed schedules when appropriate .. providing that the folks doing the sums are competent. Unfortunately that doesn't always apply from what anecdotes I hear from time to time ..
If you Take Off from a relatively flat area, the my risk assessment would say that the directional control stability could be of higher importance.
Concur
If you take off from a field surrounded by high obstacles / terrain, my personal risk assessment brings me to believe that the worst danger is the terrain.
Caveat - if the sums have been done competently and the monitored performance is appropriate (we do all know what sort of ROC we are looking for on the day, don't we ?) then, in the absence of some obvious performance problem (is the actual wind significantly different from what was anticipated ?), terrain clearance isn't likely to be of any real consequence .. which should increase the control problem risk potential in the HRA.
On the B737-NG
As I made clear, I cannot speak specifically to the NG as I didn't fly it. However, with a rapid thrust increase, 15kts might end up being diddly squat as a buffer regardless of Type and Model.
But if you, John, want to be super-safe
Not looking to be super safe - life is a risk whichever way one looks at it - only as safe as I can reasonably achieve. Knowledge of these various and oddball things is quite material to that aim, I suggest.
Greetings from a newchum!
Welcome aboard the Tech Log sandpit.
well, it sounds a bit like ssg
Come to think of it, we haven't seen our friend around for quite some time, now ...
May I commend PEI_3721's and Denti's repective commentaries, immediately above, to the readership ?