FMC altitude error P3DV3

[ShezA 176]

So I am not a newbie to the FMC world having a few other payware aircraft which I am very familiar with.

 

1. I am following the Tutorial 1 to the letter on the flight KLAX-KLAS. Route is OSHNN6 DAG KEPEC3 FL270.
2. I fill in the fuel (short flight) and payload
3. I fill in the flight plan
4. I fill in the perf init page as directed, cost index 85, FL270
5. Activate
6. I get an insufficient fuel warning and an unable next wpt and an unable crz alt warning
7. I check the LEGS page and get some strange altitudes for the waypoints like 1233ft, 2343ft and so on to a max of 4320ft halfway to KLAS

Obviously with the climb profile in point 7 above at such a low calculated altitiude the FMC will determine I don't have enough fuel because I am burning it up...

 

What am I doing wrong?

 

Shehryar Ansari

[scandinavian13 5,192]

 

 

I am following the Tutorial 1 to the letter on the flight KLAX-KLAS.

 

What Tutorial 1 are you referring to? Our Tutorial 1 is a flight into Dubai...

[ShezA 176]

Yes correct but I am following the same procedures other than the route.

 

Shehryar

[scandinavian13 5,192]

 

 

Yes correct but I am following the same procedures other than the route.

 

Probably an issue with how your flight plan is entered, then.

[pcubine 143]

 

 

Yes correct but I am following the same procedures other than the route.

What model of the T7 are you using and what is your payload?

[ShezA 176]

The model is the PMDG livery B777LR and the payload is random but the ZFW is around 400K lbs. I use fuel around 58K lbs.

 

As regards the cost index, could this value be impacting the climb rates? I tried the LOOP8 SID there are altitude restrictions on the climb out and the KEPEC3 has altitude restrictions from FL240 down to 8000. The FMC legs route shows a very low altitude for the initial waypoints then a jump to the hard altitude restriction at LAX of 10000 then a drop to low altitudes again. Could it be that the cost index of 85 might not be allowing the aircraft to climb at a good rate? Or maybe there is some other setting which I may have which is not allowing the climb to cruise.

 

Shehryar

[pcubine 143]

As regards the cost index, could this value be impacting the climb rates?

At a TOW of about 430000 lbs. I can't imagine the CI having any impact on the climb. PFPX using a cost index of 40 shows your cruise altitude is FL410. Below is the first page of the PFPX OFP.

 

 

 

 

 

What am I doing wrong?

Do Tutorial 1 using VRMM-OMDB just like it was written and then you will see what is wrong.

[ShezA 176]

Good advice. Let me do that and report. Thanks.

 

Shehryar

[ShezA 176]

Followed the tutorial, same result. Here are the FMC screenshots.

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20610&authkey=!AMpRV6tQKgH2nsI&v=3&ithint=photo%2cJPG

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20610&authkey=!AMpRV6tQKgH2nsI&v=3&ithint=photo%2cJPG

[scandinavian13 5,192]

Followed the tutorial, same result. Here are the FMC screenshots.

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20610&authkey=!AMpRV6tQKgH2nsI&v=3&ithint=photo%2cJPG

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20610&authkey=!AMpRV6tQKgH2nsI&v=3&ithint=photo%2cJPG

 

Why did you modify your climb profile?

[ShezA 176]

Where did I do that?

[downscc 1,327]

Full name on all posts... I've been lurking to see what comes of this.  First, KLAX-KLAS is a very short route for a B777, normally flown by B737s reaching FL290 barely before TOD; however, it is possible to set this up and fly it in the PMDG B77L without problems.  You are having problems, therefore everyone is trying to help you sort it out.

 

Your climb page of the FMS indicates a TA of 11000, leading us to believe you have modified your climb either on this page or in the LEGS pages.  The TA in the US is always 18000.

 

Maybe you have a bad saved panel file, or maybe your weather engine is providing unrealistic temperatures at altitude.  We can only guess how your flight is being corrupted without more information.  Are you able to complete the Tutorial flight to OMDB without problem?

[ShezA 176]

Full name on all posts... I've been lurking to see what comes of this.  First, KLAX-KLAS is a very short route for a B777, normally flown by B737s reaching FL290 barely before TOD; however, it is possible to set this up and fly it in the PMDG B77L without problems.  You are having problems, therefore everyone is trying to help you sort it out.

 

Your climb page of the FMS indicates a TA of 11000, leading us to believe you have modified your climb either on this page or in the LEGS pages.  The TA in the US is always 18000.

 

Maybe you have a bad saved panel file, or maybe your weather engine is providing unrealistic temperatures at altitude.  We can only guess how your flight is being corrupted without more information.  Are you able to complete the Tutorial flight to OMDB without problem?

I appreciate the help.

 

I think the messages are getting mixed up. Message #9 above was from my attempt to do the VRMM-OMDB tutorial flight which has a TA of 11000, that is why it has been amended. The weather is clear skies. Here is another screenshot of the FMC showing the LEGS page which has very different altitudes from the tutorial flight.

 

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20608&authkey=!ABHaJU3XE1YWGRA&v=3&ithint=photo%2cJPG

 

Thanks.

 

Shehryar Ansari

[pcubine 143]

 

 

Here is another screenshot of the FMC showing the LEGS page which has very different altitudes from the tutorial flight.

If you can still do it, could you post a screenshot of VNAV page 2 of 3. I believe the page is entitled "ACT ECON CRZ."

[ShezA 176]

Sure thing. Here are three images of the VNAV pages 1, 2 and 3 and the cockpit. Left TA at 18000.

 

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20619&authkey=!ACrv8-ffxMNf3aQ&v=3&ithint=photo%2cJPG

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20611&authkey=!AJQ5yrc_72b29u8&v=3&ithint=photo%2cJPG

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20612&authkey=!AH1iBOdmmZ3BgS4&v=3&ithint=photo%2cJPG

https://onedrive.live.com/redir?resid=ECB38A05B7CC819E!20613&authkey=!AAfyP9SBibBuVZk&v=3&ithint=photo%2cJPG

 

Interesting to note that there is an error showing on Line 2 on the VNAV page 1 above...

 

Shehryar Ansari