How fast does a real airliner climb to reach altitude?

From FlightSim

Q:

I know that airliners like to get to 10 to 15 thousand quickley and will climb at 2.5 to 3 FPM. What I would like to know is the average FPM they use after that to reach altitude. Also I would like to know what average FPM they use in decent.

A:

Hi Dan!

As a matter of fact, in airliners, when you climb out, you maintain Maximum permissible Climb power on the engines (Autothrottle can be delegated this task). Then Either by manual flying or Autopilot you maintain an optimum climb speed till about 29000 -30000 ft from whereon you start maintaining an optimum climb m No.

Max power for engine performance. Optimum speed/M No combo for max Airframe performance. These two ensure a overall max climb performance. Generally climb speeds/M No vary from 270 kt to 340 kts/ .76M to .84M depending on the type of plane. You accept whatever the rate of climb you get. The rate of climb obviously will depend on the type of plane, weight,climb schedule chosen etc. It can vary anything between 2000 to 4000 fpm at the start and gradually keep reducing as you go higher and higher from the start figure till you reach the height where you start maintaning the M No where it will increase again since you will from now on will be dropping speed to maintain the climb M No. At heights you wont get much rate of climb as good as that was at lower levels. May be 500fpm to 1500 fpm. Obviously at your max height you will not be able to climb at all since all your power will be used up in just trying to maintain height and speed itself leave alone climb. The ATC requirements state that if you request for any altitude, you should be able to maintain a minimum rate of climb of 500fpm to that altitude.

Descent is done by throttles at Idle and at your descent m No/speed combo similar to the climb combo. Generally this gets you an average rate of descent of 2500 fpm descent.