Simviation Forums

okay, well to descent i think the speed is 270kn? so when im at say 350 fl and i wanna begin my descent in my 747, the pitch goes worryingly high..and sometimes i stall...could anyone give me a proper breifing to descending? thank you

If you use the default ATC and they tell you to start descent remember that they expect you do descent at a rate of 1800 feet per minute (normally). As for the speed, over 10.000 feet you can hold the speed you like, while under 10.000 you must reduce to 250.

What said above may not apply for on-line ATC nor add-ons ATC's (the like of Radar Contact).

Usually, while landing, slow down to 220~200 (depending from the plane used) as soon your instruments signal LOC alive (or at 25nm from the airport in a visual approach) and, as soon as the Glide goes alive too (or you can see the PAPI, in visual approach), gear down and flaps. Final landing speed depends on the plane exclusively.

270kts is a slow descent number for such a large bird as the 747.
The reason I say that is because it's a heavy bird and a 270kt descent limits the descent profile to be very shallow.
(keep in mind the flap 1 speed limit is 280kts...)

I advice you to descent with a mach-number first, like M .84, and later change over to knots indicated (preferably around 300kts). So when M .84 equals 300kts on the speedtape you will switch to 300knots on the autopilot.

Initial vertical speed can be set to ~ 2500ft/min, and then you have to reduce it as you get down in altitude (otherwise you will overspeed)

These are generic numbers, most flights have their individual sets of descent speeds, but these numbers are common.
Other posters may have other speeds, and I wont argue with that as there are no rules for descent speeds (other than 250kt limit below FL100).

Use this as a reference, and modify them when necessary  :)