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Guest daryan

FMC Descent/Approach Speeds

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When I program a route on the FMC with an ILS approach and corresponding STAR the LEGS display shows a decreasing altitude as well as decreasing speed as to be expected. That said the auto throttle/auto pilot doesn

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Hello Mr.? You need to sign your name to your posts, thank you. At G/S capture VNAV disconnects and the speed window unblanks showing the current commaded speed. If you desire it to keep a speed, you have to have the A/T on and speed button selected and tune it to your desired speed. An ILS does not know what speed you need to fly the approach at, that is for us the pilots to program and monitor. Best 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 |

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Sorry my name is DavidPlease note with my first post approach mode is not selected and at no stage does the auto throttle disengage from FMC SPEED to MCP speed. I would have thought being in FMC SPEED mode the FMC command speed as per the legs display would be maintained.Thanks for your reply.

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Have you chosen your APP REF yet? What does the legs show? The issue here is not know how you have your flight setup. The FMC will keep the speeds from the LEGS pages but you have to show that the aircraft is flying something other than what is on the FMC. Got a screenshot at this point of the FMC open with the panel? Would help greatly. Best 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 |

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Approach Ref is set. I'll get a screen capture of what I'm talking about.Thanks

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Here is a screen capture you will see that the active LEG is CNNTI 160 kn @ 900 the prior leg was around 200 kn yet the CMD speed is 230 kn not 160. I also noticed that the speed mode on the AH changed from FMC Speed to ARM in white around mid base before the turn to final.http://forums.avsim.net/user_files/86979.jpg

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Get what your're saying. To me it looks like you're just going straight to the runway from the descent, without lining up for the runway.First try pressing VOR/LOC before catching the G/S and the plane should "chase" the localizer when it becomes active to fly the runway heading until you get the G/S.Or, go into the Map view on the default FS and look for the VORs/DMEs in front of that runway. Most major airports have at least 2 VORs or DMEs that will run 1 in front of the other (like point A to point :( to help line up with the runway. Enter those in your flight plan run before runway and those should get you lined up with the runway fine. Sorry if you don't understand, but I explained it as best as I could.Nick 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

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Ah ok, I see right away the issue ;-) First thing to understand here is that your speeds are only predictive not restrictive. The FMC is going by the 240/10000 restriction which you will see on the DEScent page but since your speeds are not BIG they do not over-ride this restriction. If you want to make the FMC follow those speeds, input like this 160/900A, the speed will appear in BIG fonts which is a restriction, not a prediction. Always input a speed restriction with an altitude. Of course in RL you can have only a speed restriction without an altitude but not in this sim. A little bug if you will (not really it is just not currently modelled but is known). Also keep in mind that when glide slope becomes active speed is no longer controlled by VNAV because the active PITCH mode is now G/S.Best 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 |

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Ok so thats whats happening, couldn't quite work out why the plane wasn't slowing down automatically in preperation for final approach.Thank you all very much for your help.Best RegardsDavid

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Hmm, so put an A after the altitude if it's an restriction? Never knew that one, always that it was a restriction without it.Nick 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

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Not talking about ALTITUDE Nick ;-) only SPEED and was using his example. You can have an altitude restriction I believe on this sim without a speed attached but not a speed only wpt (again in RL you can).....Best 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 |

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Nick,The "A" in 160/900A tells the FMC to cross AT OR ABOVE that altitue. A "B" means AT OR BELOW and no letter means AT.

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