question on planning a descent?

[rajiv2]

i had to ask how can you plan an accurate descent and its fpm ? beac fs9 had a steep descent and i always have an overspeed in my guage. is 2500fpm descent is better if flying a jet or a turboprop?
need help!!! thnx

[BiggBaddWolf]

2500 fpm descent sounds like a lot for any aircraft  :o

Usually in a heavy I only descend 1500-1800 fpm.
I saw a post on this awhile back, but you have to plan your descent according to the DME from the airport and how many fpm you plan to descend, figuring out how many minutes to the airport and how long it is gonna take to descend to your target altitude. Maybe someone else can help you out a little more, because I usually fly GA single and twin engine aircraft, and the normal descent for most of those is in the 500-700 fpm range  ;D

[beefhole]

It depends how you are flying (ILS approach, full visual, etc.).

[wji]

The first thing realworld pilots do upon initiating a descent is reduce power; conversely, to initiate a climb power is increased.

In MSFS the default rates can be changed by editing the aircraft.cfg; e.g.,

[autopilot]
autopilot_available=1
flight_director_available=1
default_vertical_speed=1800 change as required

I always liked the MSFS2k2 B744 descent instructions which stated: "Close the throttle."

Bill
p.s. remember if using speed-control, use KIAS (not Mach) below FL290

[Nexus]

Some answers to your question can be found here
http://www.simviation.com/cgi-bin/yabb/ ... 08;start=3  :)

[Rocket_Bird]

Depends on the aircraft.  I like to usually go between 1200-1500 on my general aviation aircraft and like 4000+ in my Fighter Jets  ;D

[gw]

To decide when to descend the rule of thumb found in the learning center works pretty well:  Drop the last two zeros from your altitude and divide by three.  30,000 feet becomes 300.  Divide by 3 gives you 100.  This is the number of nautical miles from you destination to begin your descent.  This puts you on a descent of 3 degrees.

How fast to descend depends on how fast you want to get down.  You could just stand the plane on its nose and be on the ground in a few seconds.

If you want something more realistic then here's another rule of thumb:  Multiply your ground speed by 5.3.  A ground speed of 400 kts times 5.3 gives you 2,120.  This is the number of feet per minute that you need to keep you on a 3 degree descent slope.

At first I made a table of ground speed versus descent rate and it worked out pretty well.  After a while, though I put the table away and used the divide-by-3 rule above to keep track of what my altitude should at distance from the destination.

For example, at FL300 I should be 100 miles out, at FL270 I should be at 90 miles out, at FL240 I should be 80 miles out.  From there you adjust your descent to keep up.

If I didn't explain this very well please ask.

gw