Airbus

[Spooky 2]

For those of you who are doing Polar crossing in the Airbus, does the heading ref switch to TRU automatically when entering the keyhole or does the crew manualy select TRU. What other parameters are you using with this switching?

Thanks

[ahramin]

FCOM POLAR NAVIGATION

When reaching an area where the heading reference should be changed (oceanic area, airway or polar track defined in TRUE reference ...); SELECT TRUE by pressing the NORTH REF pushbutton.

However it also says:

if an automatic MAG/TRUE switching occurs when entering the Polar zone, the autopilot might disengage due to the fact that, most probably, the automatic switching will not occur simultaneously for the 3 IRSs. The AP OFF warning is displayed on the ECAM.

I'm not sure what the conditions are for automatic switching as I've always hit the button beforehand.