I'm having an issue with the autopilot system on the 737NGX. When I attempt to use the LNAV, VNAV and CMD buttons they either don't light up or only one lights up (usually the LNAV) The VNAV never lights up. I double checked my start up procedures from loading the FMC to ensuring the pilot and co-pilot F/D's are on. I reloaded the software thinking ther might be a glitch but that didn't solve it either. Any suggestions?

 

Larry Schechter

 

 

Any suggestions?

 

Have a gander at the intro manual.

 

My guess is that you were trying to activate them when the livery had settings that prevented it.  I forget the specifics, but only certain equipment options (selected via PMDG SETUP>) allow you to select VNAV or LNAV on the ground, and only within certain tolerances.

 

If it's not working on the ground, take off and try then.

 

Try the tutorials to ensure you're operating the aircraft properly.