My assessment is that we have juuust about enough thrust to pull the skin off a rice pudding ( 100fpm + the margin you have described earlier)
Edit: misread it like you meant I had described that we have a +100 fpm margin, I'll leave first part of the reply unchanged anyway:
No, I didn't - on the contrary, I said we have a lot higher margin because the +100 feet is calculated at LRC, where we have a higher drag than the Vmd. Hence, flying at Vmd the residual climb rate would be higher than as calculated for LRC.
Plus, the +100 feet is calculated at CRZ thrust limit. With CON you have 4% extra N1.
Hence, my assessment is that you greatly underestimate the thrust available.
Again I quote the FCTM:
On airplanes with higher thrust engines, the altitude selection is most likely limited by maneuver margin to initial buffet.
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if we suddenly gain twenty knots of tail, or lose twenty knots of head, or if the temp increases, or we experience wake or other turb, we may find ourselves having to descend when we are not cleared to. I don't expect these things to occur very often, maybe once or twice a decade
What is "suddenly"? If you mean
instantly - then you would with 99% have had forewarning. The wind doesn't change 20 knots instantly in smooth conditions. Or like I said before, it is just as likely as meeting Godzilla at FL380.
I do maybe 250-300 flights
pr. year or up to 3000 flights in a decade. Will I make all 3000 flights is FL100, because of the odd chance I might experience a pressurization problem? Of course not, to me this is similar in likelihood.
Even if I had to descent, a quick call to ATC, "unable to maintain speed, require descent", may often be in time to avoid having to make a
mayday call (pan call - urgent message- will get you nowhere, and does not allow you to deviate from your clearance - but that's a different story
). Remember, you do not need to make an emergency descent with 4000 fpm sink rate, a shallow descent to the non standard level 1000 below will with all likelihood be enough to regain your speed. Or maybe 1-200 feet will even be enough and you can do that on your own, without even bothering the ATC controller.
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And now for something completely different (as Monty Python would say):
The Boeing performance Engineers say this:
“All right,” you say, “we'll just calculate the fuel flow at the speed for minimum drag. Minimum drag means minimum fuel flow, right?”
To whom are they talking? Who is this "you"? Clearly, it is someone who didn't do his ATPL:
Min thrust required = Max Range Cruise
Min
Power required = Max Endurance
This is really basic ATPL knowledge and I really don't know why you bring Max Endurance into the picture. But I will follow your lead...
Boeing has given the pilot the best theoretical speed for staying in the air the longest time possible but practically it is rarely that
On what do you base this assumption?
What is "BEST SPEED"? I have never heard of "BEST SPEED" before, "best speed" for what?
I have a target speed on the holdings page with is "Max Endurance" or "Min Power Required" (at least ≈ , to avoid making it too complicated). If indeed you mean target holding speed from the FMC holdings page, it just shows how much thrust you mostly have available, since it will be just a few knots above the amber band. I wouldn't personally want to fly at that speed at high altitude though, since a 1-2 knots margin to the amber band is on the low side for me (yes I know I am being conservative and that I still have 1.3G margin to stick shaker).
...but the again, who holds at FL380?
