Jump to content
Sign in to follow this  
jumboross

744 not descending?

Recommended Posts

Hello AllI've been back to the 744 today after some time away. Have done two flights with properly programmed FMC with SIDs and STARs etc and have had the same problem twice, so I'm guessing it must be operator error?The aircraft takes off and climbs as it should with LNAV and VNAV engaged, then carries on to cruise as planned. The problem comes at the top of descent, or rather where the top of descent should be. As I reach and pass the little green 'TD' sign on the screen the aircraft just keeps flying at cruise altitude and speed (it does however keep to the correct LNAV profile, i.e. it continues following the purple line). On both occasions I made sure the MCP altitude was set to the next planned waypoint lower altitude. I presume I'm doing something wrong but can't seem to work it out? I've searched the forum and haven't found the same specific problem.Any help appreciated.Thanks,James.

Share this post


Link to post
Share on other sites
Hello AllI've been back to the 744 today after some time away. Have done two flights with properly programmed FMC with SIDs and STARs etc and have had the same problem twice, so I'm guessing it must be operator error?The aircraft takes off and climbs as it should with LNAV and VNAV engaged, then carries on to cruise as planned. The problem comes at the top of descent, or rather where the top of descent should be. As I reach and pass the little green 'TD' sign on the screen the aircraft just keeps flying at cruise altitude and speed (it does however keep to the correct LNAV profile, i.e. it continues following the purple line). On both occasions I made sure the MCP altitude was set to the next planned waypoint lower altitude. I presume I'm doing something wrong but can't seem to work it out? I've searched the forum and haven't found the same specific problem.Any help appreciated.Thanks,James.
Hi James!If you selected the next lower altitude on MCP as you said (before reaching T/D)....did you check in your CDU that, you also had a lower Altitude when passing that fix?I guess, you did, but can

Share this post


Link to post
Share on other sites

What is the FMA saying? The annuciator is the first place to look when you don't understand what the boxes are doing.


Dan Downs KCRP

Share this post


Link to post
Share on other sites

This happened to me once, and I figured out that it was because I had a holding pattern programmed into the FMC. Once I deleted the holding pattern, the plane then recovered to capture the VNAV descent profile and everything operated as normal from there on out.


Scott Kalin VATSIM #1125397 - KPSP Palm Springs International Airport
Space Shuttle (SSMS2007) http://www.space-shu....com/index.html
Orbiter 2010P1 http://orbit.medphys.ucl.ac.uk/
 

Share this post


Link to post
Share on other sites

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
Sign in to follow this  

  • 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...