VNAV and TOD

[mokeiko 39]

Hi everyone,

I am at eg. FL380 and 2 Min. Before TOD I change ALT to next way point ALT. Am I supposed to left click the ALT knob at TOD? The reason I asked is because the aircraft does not descend at TOD, it just keeps flying level. 

I am following the tutorial and it does not mention if I’m supposed the left click the ALT knob or not. What do you guys do? Thanks for any help.

fly safe

 

[Budbud 227]

Hi.

No, you don't have to press the ALT button to descent at the TOD if you have selected a lower altitude normally.

What is the pitch mode displayed on the FMA? It should read VNAV PATH and it is required for the descent to occur automatically at TOD as per above.

If VNAV ALT is displayed instead (which would not normal at this stage) then you need to press ALT.

If anything else is displayed, verify the VNAV is engaged as it is required for the automatic descent with a lower level selected on the MCP.

 

 

[Ephedrin 418]

On the right side of the ND you see a magenta display showing the v path relative to your airplane‘s altitude. As long as it is centered and your FMA says vnav path everything is fine. How long have you been waiting until you intervened? The 747 likes to decelerate pretty long before starting its decent on low company indexes... i have noticed that up to 10-15 miles before the nose went down. My vnav path was perfectly centered as the TOD moves closer to the destination when you become slower.

[mokeiko 39]

Thanks guys, I will try another flight this evening.

fly safe