VNAV in 747-400 QOTS

[Guest nickallan]

Hi,I bought the Queen back in August, but have just got round to flying her, due to that nasty thing called work :-( I seem to get everything else right, but I can't get any of the A/P (VNAV) to work. I have followed the manuals and the tutorial to the letter (or so I think!!), but nothing works. I take off from EIDW on a short hop to EGPH. Everything is loaded. I take off from Rnwy 28 using TAGO setting. Take off is nice and smooth. I activate the AP and also LNAV and VNAV. The aircraft banks to follow the FMC flightplan, but I always get VNAV Speed in the EFIS. According to the manual I should just have plain VNAV or VNAV Alt (I think). Anyway the aircraft climbs at 4500 fpm and is only limited by the speed reaching stalling speed. I have an initial alt of 6000ft in the MCP, but the aircraft flys straight past this and on and up.I am probably missing a trick and being really stupid, but I can't seem to find what I have done wrong.Any help is greatly appricaitedNick Allan

[michal 44]

There is no such thing as "plain" VNAV (check the manual). It is either VNAV "PATH", "SPD" or "ALT". During climbout you will always have SPD/ALT. On descend you may get PATH provided there are *some* altitude restrictions in your flight plan in the descend leg. Also PATH is conditioned on you staying within the prescribed speed.Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2http://www.precisionmanuals.com/images/forum/747400.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

[Guest nickallan]

Thanks Michael.I managed my first flight - I don't know what I did right :-), butI had to use fltchg at first before I could get the vnav spd to activate properly. Then I was at cruising alt and the plan started to dive and swerve off course!. I managed to switch the a/p off and then back onn and this seemed to resolve it. Am I doing somehting strange!!Nick Allan

[michal 44]

>Am I doing somehting strange!!Most definitely. ;-)Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2http://www.precisionmanuals.com/images/forum/747400.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

[Guest aarskringspier]

>Hi,>>I bought the Queen back in August, but have just got round to>flying her, due to that nasty thing called work :-( >>I seem to get everything else right, but I can't get any of>the A/P (VNAV) to work. I have followed the manuals and the>tutorial to the letter (or so I think!!), but nothing works. >>I take off from EIDW on a short hop to EGPH. Everything is>loaded. I take off from Rnwy 28 using TAGO setting. Take off>is nice and smooth. I activate the AP and also LNAV and VNAV.>The aircraft banks to follow the FMC flightplan, but I always>get VNAV Speed in the EFIS. According to the manual I should>just have plain VNAV or VNAV Alt (I think). Anyway the>aircraft climbs at 4500 fpm and is only limited by the speed>reaching stalling speed. I have an initial alt of 6000ft in>the MCP, but the aircraft flys straight past this and on and>up.>>I am probably missing a trick and being really stupid, but I>can't seem to find what I have done wrong.>>Any help is greatly appricaited>>Nick AllanIve had this where engaging VNAV put me into a stall; I had to re-install and havent had it since. Just chalked it up to a funky install.

[Guest D17S]

Hey michal, Like you were saying, remember we were taking that Vnav always climbs in 'Vnav Spd?' 'Vnav Alt' means that the airplane captured an altitude set in the MCP's altitude window before the FMC's cruise alt and 'Vnav Path' was for VNav cruise page captured altitude and Vnav decent.