F/D misbehaving !

[teropa]

Hi,Not trying to "diss" good ol' PIC, just trying to understand these things (ref. G/A thread). ;).The problem:At Acceleration Altitude, after selecting VNAV (which engages immediately), the F/D will NOT command pitch down for acceleration, but instead stays up to command takeoff "mode" pitch, ie. 15-25 degrees ANU. What I'd like to see that it would command nose down after AAL (ie. right after VNAV has been selected), so that one could follow F/D in bad conditions as IRL. Now the F/D stays up there when I pitch the aircraft down. Interestingly, it WILL command nose down at FL100 for acceleration to 300, but NOT nose down for acceleration to 250 below FL100 (as should, to accelerate and clean up the aircraft).I have selected 1500 as acceleration altitude, as per Finnair SOPA. And I select LNAV passing 400ft AAL and VNAV passing 1500ft AAL, after which the acceleration should immediately start. But it won't.If I select FL CH or another pitch mode, the F/D will behave properly, the acceleration is the only thing that "bugs" me here.Comments again, anyone ?Terops. could the fact that I'm altering the standard Boeing acceleration altitude from the preset 1000ft to 1500ft in the CDU have anything to do with this ??

[Guest Mark McG]

Tero,not sure if changing the acceleration height alters things.What I do is VNAV CLB PAGE V2+15/1500 or 3000 as a restriction.When I engage VNAV I get the correct pitch commands. Normally I have V2+15 to 3000 ft.Later

[teropa]

Mark,I tried setting (V2=140) 155/1500 in VNAV CLB page, and it worked!After 1500 it started to accelerate to FLAP5 placard speed (=220).However, this is not how the real aircraft performs, the selection of Acceleration height=1500 in TAKEOFF page 2 should do it.Additional question.What am I supposed to type in the TAKEOFF ref page in the TOGW field ? I had a Gross WT of 120t for my test flight, so I just copied that figure to TOGW field, and it showed "264" or something right after, and said "V-SPEEDS DELETED". However, the speeds looked similar to what I had before that "maneuver". What is the purpose of that TOGW field, and why did it show 260 something (quickly figured, that's about right for 120t in LBS, a bug ? As I'm using metric, maybe that field was supposed to show the Gross WT of 120t anyway?)Tero

[Guest Mark McG]

Tero, just fired up the sim to have a look at this. Here's what I figure - only shows the TOGW in LBS, but only accepts entry in KGS if using Metric. I reckon that this is to get more accurate V speeds, taking into account what fuel you would expect to burn for taxi, although it shouldn't change that much.

[Guest ATPBVC]

Are you getting this from a cold and dark setup or on the second flight. Wgy? I have noticed that if you shut down, you will have no problems, but if you load a second flight into the FMC without a full shut dn, you'll get some unfavourable results.

[teropa]

Bill,I have saved a flight with Finnair 757 (only the model!) standing at EFHK gate26, with cockpit in a real-life cold & dark config (which does not mean that everything is turned off). This is where I start all my flights.Tero

[Guest Mark McG]

Tero,I start from full Cold and Dark cockpit.

[teropa]

Guys,You have to understand that the "cold&dark" as provided by the old PIC loadable flights is not something one would ever see on a secured B757/767.If anyone wants, I can take screenshots of all the parts of the panel, how it should be left when the aircraft is secured (ie. cold & dark).Tero

[Guest ATPBVC]

Tero 757? This could be the problem? What Air File? PIC?You can not fly 757 numbers on 767 Air file.

[teropa]

Bill,from my previous message:"I have saved a flight with Finnair 757 (only the model!)" Yes, I'm using PIC767 FDE. Everything is PIC767 except the aircraft model. Are you saying you will get perfect F/D operation for acceleration without editing VNAV CLB page for additional speed restriction ?Are you seeing a significant F/D nose down command once passing acceleration height that you have set in the CDU ?Tero