Jump to content

FMC during DECENT


Guest 170525

Recommended Posts

Posted

With PMDG (and LEVEL-Ds) FMC i need to ajust FL manually during decent by decreasing altitude according to next leg. this seems illogical since this is an automatic FMC system.my questions are:1) is this normal?2) if not normal, how to operate/set so that decent happens according to (FMC) calculations?3) if normal, why is it so (i guess its so for a reason)?i ask that if you reply, pls reply with some relevance to this technical question.thx

  • Commercial Member
Posted

Hi I'm not sure I fully understand you but. The Aircfaft still needs pilot input, nobody wants to be 100% out of the loop. I think if you ask most real world pilots they would prefer to initiate automatic climbs and descents themselves.How it should work is at T.O.D you select the altitude you require (which could vary from the pre programed altitude due to ATC requests) and then wait for VNAV to kick in or select your own method eg V/S FLCHRob

Rob Prest

 

Posted

>With PMDG (and LEVEL-Ds) FMC i need to ajust FL manually>during decent by decreasing altitude according to next leg.>this seems illogical since this is an automatic FMC system.>>my questions are:>>1) is this normal?>2) if not normal, how to operate/set so that decent happens>according to (FMC) calculations?>3) if normal, why is it so (i guess its so for a reason)?>>i ask that if you reply, pls reply with some relevance to this>technical question.>>thxIt is normal, and will allow the FMC to fly the programmed descent profile, just requiring YOU as PIC to permit it to do so. As Rob indicates, the system is even smart enough to request a MCP ALT change- and when you do so, it will fly the profile perfectly.The reason it waits until you "allow" it to fly the programmed descent, is that in the RW, ATC will frequently (for separation and a myriad other reasons) create a situation requiring an early or late descent. In that case, were the aeroplane to do what was programmed, catastrophic consequences would result. As you are cleared lower and lower by ATC you dial in the cleared ALT and the MCP flies the profile to that altitude. Should it have ALT HOLD due to a non cleared altitude, depressing the ALT know will allow for resumption of the descent. Keep in mind the same philosophy applies for the climb.Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 with FS-GS System Unification | 2 x APC UPS | Coolermaster Stacker 830 SE | Asus P5E-Deluxe (X48) | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Sony 40" Bravia XBR | 2 x 1 GB Corsair XMS2 | 500GB Seagate Barracuda 32MB SATA2 x2 (Acronis) | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |

Best-

Carl Avari-Cooper

Posted

thx for the replies. it makes sense with regard to the ATC. guess i'm too used to flight without ATC in FS2004 (which is poor ATC at the best - in my humble opinion).thx again:-)morten

Posted

............all the more reason to discover VATSIM!Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 with FS-GS System Unification | 2 x APC UPS | Coolermaster Stacker 830 SE | Asus P5E-Deluxe (X48) | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Sony 40" Bravia XBR | 2 x 1 GB Corsair XMS2 | 500GB Seagate Barracuda 32MB SATA2 x2 (Acronis) | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |

Best-

Carl Avari-Cooper

Posted

............all the more reason to discover VATSIM!Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 with FS-GS System Unification | 2 x APC UPS | Coolermaster Stacker 830 SE | Asus P5E-Deluxe (X48) | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Sony 40" Bravia XBR | 2 x 1 GB Corsair XMS2 | 500GB Seagate Barracuda 32MB SATA2 x2 (Acronis) | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |

Best-

Carl Avari-Cooper

Posted

All that I would like to add is re the FMC DES FORECAST page.For my descents from FL300+, I enter wind speeds and directions into the forecast page. This usually gives a very accurate descent on the (modified) profile, and usually means no speed braking is required.I obtain the descent winds forecast from the REPORT page of ASX, and enter winds for FLs 300, 240, 120 and 010.Of course, if there is ATC on duty, you may get descend/maintain instructions which confound your careful planning but, hey, that's the real world.Hope this adds to the enjoyment,Cheers, Richard

Cheers, Richard

Intel Core i7-7700K @ 4.2 GHz, 16 GB memory, 1 TB SSD, GTX 1080 Ti, 28" 4K display

Win10-64, P3Dv5, PMDG 748 & 777, Milviz KA350i, ASP3D, vPilot, Navigraph, PFPX, ChasePlane, Orbx 

Posted

thx again for replying. just so that i'm sure: these ajustments are made if you are using VATSIM, yes? when i started flying, i used FS2004 FlightPlanner. after starting with PMDGs FMC its close to impossible to plan anything combining FlightPlanner AND the FMC.i have ended up planning almost all flight with the FMC, excluding FS2004s FlightPlanner, but that complicates arrivals. sample: if i arrive from FL36 to whatever aitport, i have to start decent and plan for several runways until i'm close enough to receive ATIS weather report - and finally what runway thats active. i'll have a look at VATSIM (never used it before). any advice on what software to use?:-)thx again

Posted

It is a rule of this forum that you use your proper name. Please do so, it makes the conversations so much more personal. Ta!If I understand you correctly, you 'use' VATSIM by installing SquawkBox v4 (SB4). Just google it to find it.To use SB4, you must join VATSIM to obtain a userid and password, which you will then have to enter into SB4. Again just google VATSIM and read all about it.In VATSIM, you will join the many thousands of pilots who fly on-line. It's a great experience.Cheers, Richard

Cheers, Richard

Intel Core i7-7700K @ 4.2 GHz, 16 GB memory, 1 TB SSD, GTX 1080 Ti, 28" 4K display

Win10-64, P3Dv5, PMDG 748 & 777, Milviz KA350i, ASP3D, vPilot, Navigraph, PFPX, ChasePlane, Orbx 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...