One last topic of discussion. I sometimes have an issue engaging the autopilot or VNAV. Yesterday I took off and clicked on VNAV but nothing happened. I took off from SLC and climbed out 1,000 ft from the airport altitude but no luck. I tried several time but couldn't get it to work. I ended the flight and started over. The second time I got VNAV and LNAV to work but the CMD A wouldn't go. I let go of the yoke based on a discussion I saw at the i-fly 737 forum that said to make sure there was no pressure on the yoke. I tried that but it didn't work either. Prior to these attempts I successfully got all three to work while using the yoke so I'm not sure where things are going wrong. Can someone help with this? I'm sure I'm not doing something right but I can't figure out what.

 

Larry Schechter

 

 

Can someone help with this?

 

Intro manual for the restrictions on AP use and LNAV/VNAV arming. Tutorials for the procedural parts.

 

The basics?

The airplane needs to be in trim (or if you don't want to bother with this, turn the REALISTIC AP ENGAGEMENT option off in the PMDG SETUP> menu of the FMC), the LNAV track needs to be within a narrow margin of the departure heading (I forget the exact number at the moment), and other items that are seemingly escaping me at the moment.

 

Usually, when automation is "intermittent" as you're experiencing, the cause of the issues is usually a human factor.

Yeah, I kinda figured it was pilot error. Thanks for the tips.