Hi All,I did a search but could not find my issue. I have the latest Service Packs etc.When flying without the FMC, and coming up on the LOC. If I hit the APP button, it does not seem to light and stay lit, but does follow the APP decent.Any ideas?Thanks,

This happens in the real aircraft and is supposed to happen for a reason which I hope I can demonstrate here! The lights in the buttons on the MCP have one purpose only, they tell you that you can deselect that mode by pushing them! ie if the LVL CHG button has a light in it illuminating the 'ON' Caption then you can push it and the LVL CHG mode will be de-selected. This is contrary to many people's belief that these lights are the way you tell which mode you are in. Yes in the default MSFS 737 you can only tell which mode you are in my the lights but the PMDG model and panel are far more accurate and provide us with a proper Flight Mode Annunciator (FMA) along the top of the attitude indicator. The FMA is the ONLY way to see exactly what mode the auto flight system is in! So when you are on approach and hit VOR/LOC the aircraft will capture the LOC and fly it, the light in the VOR/LOC button remains on because you can deselect the VOR/LOC mode. Then you select the APP mode and you see G/S arm in the FMA (it shows white first before it captures). As the G/S captures the APP button light goes out but the FMA will show that G/S mode is active as it has gone green. Basically the APP mode cannot be disengaged by pushing the APP button once the G/S has captured hence the light goes out! The simple way to look at this problem is to discount the lights in the MCP as a way of telling which mode you are in. The ONLY way to see what mode the AFDS is in is by looking at the FMA along the top of the attitude indicator display!!Hope that helpsKris

OK, that makes total sense. I thank you! :)Really appreciate the clear answer. Now to see if I can fly this thing :)Cheers,