It depends largely on the Cost Index (that magical number between 0 and 999) which is input into the FMC. This is effectively a figure which relates costs, such as fuel or crew wages, to the flight to time. Basically a CI of zero is minimum cost and a CI of 999 is maximum speed (if I remember rightly).
We normally operate a CI of 100 which gives a climb of around 320kts/M0.83, a cruise of M0.84 and a descent of M0.825/300kts. Give or take. The rate of climb varies depending upon weight although it's normally between 1000fpm and 2500fpm depending upon the speed.
Is it possible for this bird to achieve a climb rate in the range of 7000 fpm at 250 kias ?
I've seen 4500fpm having 'zoomed' it but I'd be surprised if 7000fpm was possible. No doubt a test pilot will now prove me wrong!
