Yet another descent question....

[Guest pledford]

I have searched the forum and found several threads on the question, but none of them really answered it...When I reach the T/D and the FMC starts its descent I usually get the "overspeed" error and it kicks off vnav, then of course it asks for more drag... As i want to use the FMC for descending when should I start the T/D? 10nm, 20nm early? Is ther a step in flight planning I've missed? I could of sworn I've read somewhere that using the brakes to slow the plane down was a "unprofessional" thing to do....Sorry if this is the same ole question all over again.Paul LedfordN0418NWVA

[Mats_J 2]

Paul,Indeed this question has been answered over and over again. ;-)Nevertheless I will give you a short answer. Getting the OVERSPEED message above 10000 feet is no problem. Just let her pick up some speed and sail away. VNAV will not disconnect unless you are very close to the barber pole area (Mmo/Vmo). Below 10000 feet you have to be more careful. VNAV will disconnect if your actual speed exceeds the target speed with more than 10 (or was it 15) knots. Before that you will get the DRAG REQUIRED message.To enhance the path predictions which will give the aircraft a better chance to keep within the limits you might want to consider entering the winds aloft in the area you're descending through. This is done on the DES>FORECAST page. If you are using AS2004 the wx print out will give you winds aloft. Online data could also be used if you are using real weather.Hope it helps,

[Guest pledford]

Is there a url for this onlin data? I will also look up "as2004" Thank you for your patience,Paul LedfordN0418NWVA

[Mats_J 2]

Paul,AS2004 is short for ActiveSky 2004 availible here: www.hifisim.comThere's also a forum for ActiveSky a couple of stairs down from here. ;-)For online data almost every nation has their own meteorological institution plus a multitude of private actors. Do a search on Google using "winds aloft aviation" or something similar. Seek and ye shall find! If somebody has good links for global winds aloft please poost the links here!Hope it helps,

[Guest Nickman]

Make sure you have your autothrottle engaged. Try to turn off autothrottile, then Vnav, and turn VNAV back on.You must remember all pilots fly differently. Some pilots find that spoilers are useless and others find it is the best thing to use to slow down. I wouldn't call it "unprofessional" (I actually get a kick out of them because all the racket and vibration :(), but more controversial than usual. I've even heard of pilots using the landing gear to slow them down, so it depends on opinionNick B.Continental Airlines Virtual 737NG Pilothttp://www.precisionmanuals.com/images/forum/800driver.jpg--AMD Athlon XP 3200+ @ 2.2 Ghz (Equal to 2.8 ghz)400W Power supply3x 80 mm Case FansSoyo VIA KT600 Dragon PlusnVidia GeForce FX 5200 128 mb2 x 512 PC400100 GB Western DigitalMicrosoft Sidewinder Precision 2

[crvm 0]

Or you can choose a SPD DEScent over a PATH DEScent. A speed descent with keep your target speed and not the path profile while the default path descent mode will sacrifice speed for the path. If you input forecasts winds into the FMC it will do better planning profile etc and maybe keep you from getting too fast or too slow. Do not be hestiant to use the speedbrakes when needed. While it is true you can go as high as the barber poll this really is not good flying technique (even though I suggested it before), one reason would be the excess speed when coming upon the 250/10000 airport restriction (defaults to 240/) which most likely will cause the AFDS to kick out of VNAV for CWS or LVL CH. It's pretty much about planning and paying attention to your descent winds. Here is a descent shot, I have forecast winds in the FMC and look at my speed etc. Looking pretty good because I planned ahead.http://forums.avsim.net/user_files/87702.jpgBest Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |