Getting both LNAV and VNAV disconnect ;)

[joherszch 21]

Hi, when I load a route into the FMC, and put all the important things into it. And then when I on climb engage the A/P and push the LNAV and VNAV buttons, I get FMC First message right above the HSI. I open the FMC and get NOT ON INTERCEPT HEADING and VNAV DISCONNECT UNABLE CRZ ALT messages. Well, I must be doing something really wrong :D Because I tried 5 diffrent flightplans. CheersJohan Adolfsson

[Guest ba747heavy]

>Hi, when I load a route into the FMC, and put all the>important things into it. And then when I on climb engage the>A/P and push the LNAV and VNAV buttons, I get FMC First>message right above the HSI. I open the FMC and get NOT ON>INTERCEPT HEADING and VNAV DISCONNECT UNABLE CRZ ALT messages.>Well, I must be doing something really wrong :D Because I>tried 5 diffrent flightplans. >>Cheers>>Johan AdolfssonLNAV Engagement: You must be within 3 nm of the route, and on *any* heading, and the LNAV mode will enage and will roll the plane to the correct heading to follow the route.Or...If you are more than 3 nm from the route, your intercept heading must be < 90* and intercept the route before the active waypoint. If you fail to meet those standards, you will get the scratchpad message not on intercept heading.About the VNAV message, I think that means your T/D (top of descent) is before the point at which you will reach cruse. To fix, fly a longer route, or pick a lower cruise alt.

[joherszch 21]

Hi, LNAV works after I did as you said. But still VNAV dosen

[crvm 0]

Hello! UNABLE CRZ ALTITUDE FMC predicts aircraft cannot reach the new CRZ ALT due to performance limitations or no cruise time possible as entered CRZ ALTSOULUTION Clear the message and review CRZ ALT selection. Enter aircraft altitude or lower. FMC will not recognize descent phase untill cruise phase is attained. So, select a lower crz altitude for this particular route...[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/betaimg.jpg

[Guest nutcase]

Lower crz alt for this route? are you kidding?. It's a flight from Stockholm, Sweden to Heathrow, London. In the real world, a 737NG vil cruise at a much higher FL than 320. Even in Norway we have NG's that flies at FL 410 on domestic flights (flight between souther norway and Northern Norway)Jan Roar R

[joherszch 21]

Hi, did a quick test but I get the same message. I tried both to enter a lower and a higher altitude. But still it disconnects! Am I the only one this problem?CheersJohan Adolfsson

[Guest au-s]

are you entering the INIT page correctly ... zfw ... etc ...try maybe to not go on a full loaded plane.FL410 is reached when the airplane do not have so much weight and passengers onboard.Load the loadmanager and other option, go to FS9 and change weight settings.I dont know if thats the problem you have, You should with full loaded plane go to about FL350 Can you in short wright what you do in FMC

[crvm 0]

Please give all details, I want to know what weights etc. It's hard to shoot in the dark ;) [h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/betaimg.jpg

[joherszch 21]

Hi, took these pictures so Randy could stop shooting in the dark ;) Hope the help you to find the problem!http://forums.avsim.net/user_files/53382.jpg

[Guest ba747heavy]

>Hi, took these pictures so Randy could stop shooting in the>dark ;) Hope the help you to find the problem!>>http://forums.avsim.net/user_files/53378.jpgSir, no go on the attatchment.

[joherszch 21]

Fred, fixed the pictures :DCheersJohan Adolfsson

[crvm 0]

This flight is 231 miles. Now you are asking the bird to get up to a crz alt and have time for a descnt all within this space-time. What IS possible here? I'm sure all the performance folks can chime in ;). Here is what a little real 737 trainer shows for this exact route and what happens when I enter FL350. ROUTE ESGG-ESSA shows this message. I do not know if Nutcase was refering to this route but there is simply no way to get that high in this amount of miles.http://forums.avsim.net/user_files/53389.jpg So, the FMC is telling you at ECON CLIMB you aren't gonna make it ;) TRY selecting MAX CLIMB for FL270 and see if it will take it. Realisticly it looks like FL240 ish will be fine. The whole idea here is to work with the FMS and not ask it to completly do all the work needed. Sometimes we need to adjust various things to make it work the way WE want it too, but this does not mean that it will always let us! [h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/betaimg.jpg

[Guest bawheavy]

hey Johan!I'm sorry if im teaching you to suck eggs, but you are remembering to set your cruise altitude in the Altitude box of your MCP (autopilot) arn't you?That was the problem I had when I converted from airbuses - i didn't know you had to stick the altitude in the autopilot and it wasn't until fred brought out his tutorial that I found out!Sorry again ;)Liam

[joherszch 21]

I have tested with altitudes from FL150 to FL325 for that flight :D I never thought this was going to be this difficult!CheersJohan Adolfsson

[Guest ba747heavy]

>I have tested with altitudes from FL150 to FL325 for that>flight :D I never thought this was going to be this>difficult!Johan,Do you get this error on a longer route, say KJFK-KORD?