Hello I have this problem that when i am tasked to decend to 3900ft for the ILS of a runway i cannot select the approach button,it will not light up. I am using the DF panel merged with the new Ariane 737-500. I have flow my flight all the way using the FMC then change to using the auto pilot buttons for my final approach, also using RC3. Why cant i select the approach button to intercept the ILS. Would appreciate any help. Thanks in advance. Shaun.

You must first tune NAV1 to the ILS frequency and be near enough to receive the signal before approach hold will engauge. R-

Shaun, I just purchased the 737-500 and had the same problem on approach to KAUS. The APP button wouldn't light up. This is strange especially since I'm using the same Ariane's 737 TCAS II panel that I use in my Ariane 737-300. It works in the -300 but not in the -500????:-waveSteve

A second flight shows this to not be a problem. The -500 captured the ILS and it worked 100% correctly. Steve

Try entering the ILS frequency into NAV1 AND NAV2, works for me.Pete