View Full Version : 737NG FMC ALERT

15th Sep 2012, 17:01
Hi everyone,

I've been a long time reader of this absolutely interesting forum and decided today to start writing.

I'm currently flying the 737NG (700/800) for a southamerican carier. Today, on a flight, we got an FMC message (ACARS MESSAGE) that i had never seen. I searched the FCOM, and the web but couldn't find anything.

The message was as follows: "ICAO ADDR MIS-COMPARE"

Any thoughts?

15th Sep 2012, 17:39
Probably that aircraft is new in the fleet. The ACARS still has the old registration and ICAO address in its settings and thus cannot perform a sign on - if your company still uses the ACARS then they should get it fixed, if not, set COM 3 from DATA to something else, that should inhibit the ACARS all together (it will complain once with ACARS VOICE and then shut up). If you are curious you can look into the ACARS menu, you should find it has an old aircraft reg programmed.

16th Sep 2012, 00:21
Thank you STBYRUD. It's a new aircraft in the fleet indeed!! I'm gonna try it and invertigate into the ACARS menu.

Thank you very much for your answer.

16th Sep 2012, 09:04
1. The new 737NG aircraft's ACARS is installed with APM (Aircraft Personality Module) which stores ICAO address.

2. ACARS receives the ICAO code from ATC then compares with ACARS' APM, they shall be the same, per your description of failure, they are different in this aircraft.