When to contact tower?

[JN_]

To add yet another data point, I fly out of PHNL. While taxiing to the runway, 80% of the time they'll tell me to "monitor tower" as I get close to the hold short point. On the occasions when they "forget", I was taught by my instructor to just switch over on my own.

Perhaps it's only used at very high-traffic airports.

Generally, yes. It's much easier for the tower controller to choose which plane he/she wants to talk to rather than having every single plane call up and the controller just having to reply with "[callsign], xxx Tower, hold short runway [runway]." Especially if there is a big departure lineup where the aircraft have no where to go except to follow the plane in front of them heading for the same runway. If all of the planes were to call up when holding short/approaching the runway at a busy airport, it would just provide unnecessary congestion on the frequency.

I believe that's what "monitor tower" is for (as opposed to "contact tower"). We just switch over and hold short silently until called upon.

[arb65912]

Gentlemen, I just want to make sure I understood it properly.

In some ( most likely the busy ones ) airport, pilot might be told to monitor tower which means he will be taxiing to active silently and when holding short, he will wait for the tower to call for line up and wair or take off, correct?

Cheers, AJ

[Kyle Rodgers]

Correct.

A basic rule of thumb here, in an attempt to clear things up in all cases:
Unless otherwise told (below), switch on your own when you're holding short, and announce to the tower that you're ready.
Contact tower precludes the above, and is an instruction to announce to tower that you are now talking to them.
Monitor tower precludes the above, and is an instruction to switch to tower's frequency and wait to be called.