After extending centerline, disarm nav or leave engaged
 

Just wondering what opinions there are regarding this topic. During an approach that is radar vector, it is common in the airbus that from the fmgc, we would extend the runway centerline. After this operation the nav mode is armed whilst the aircraft if flying the heading to the intercept point if there is one. From experiance, most pilots I see instantly disarm this nav mode so the aircraft will maintain the heading assigned even if crossing through the centerline. However there are some that argue that this armed nav mode provides pilots with additional protection for example on runways with simultaneous parrallel approaches. Should the controller forget, or cannot get a word in on a busy frequency, the aircraft will establish by itself. Obviously the other method of thought is that the controller might not want you to establish and is diliberatly maintaining the heading assigned. Our ops manual doesn't mention if we should or should not leave it engaged. Good airmanship would suggest you contact ATC if in any doubt but I'm wondering what either ATC would expect from you or if some have it listed as sop.

If the controller is taking you through the centreline I would expect him to tell you.

CDG is the only airport I know where it’s SOP to intercept the extended centreline even if not cleared unless the controller has specifically not told you to. As 95% of the approaches we fly are still ILS, I’d still disarm Nav and arm LOC instead.

The only time I’ve left Nav in blue is when cleared for an RNAV approach but on a heading. I’d extend the centreline from the FAF and leave it armed.

Champ