When you get cleared for the ILS approach, you press the APP MCP button.
Question:
Does the APP light come up immediately, and the HDG light extinguishes, or does the HDG light remain ON until Localizer intercept begins?
Same question regarding APP and ALT HOLD, in relation the Glide Slope capture. When does the ALT HOLD light extinguishes? Upon pressing APP or upon capturing the G/S?
The APP light lights up immediately, and HDG light stays on until localizer capture.
The ALT Hold light extinguishes when you capture the G/S.
If you want to deselect APP mode after capture of LOC and G/S youve got three ways of doing that. Pushing APP button will not do the trick, that option is inhibited.
1. Press TOGA switch
2. Disengage autopilot and turn off both flightdirectors
3. Retune (change frequency) a VHF nav receiver.