Stamatis
ok here goes....
"Suppose you are flying level, in ALT HOLD, HDG mode and A/T SPD mode towards your ILS intercept. When you get cleared for the ILS approach, you press the APP MCP button.
Question 1:
"Does the APP light come up immediately, and the HDG light extinguishes, or does the HDG light remain ON until Localizer intercept begins?"
Answer 1. the APP light comes up immediately AND the HDG light remains ON till LOC capture.
Questin 2.
"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?"
Answer 2. The ALT HOLD light would have extinguished when you acquired your altitude ie., when you levelled off 'at your MCP Selected Altitude'. this could be your glide slope intercept altitude.
the logic for the lights is that a light on the MCP illuminates for a ARMED mode (in this case APP) as well as for an engaged mode(eg., HDG) except once engaged in certain modes the light may be extinguished to indicate the mode cannot be deselected.
hope this helps....
