Originally Posted by
aterpster
airbubba:
Check the note referenced with "#." Jepp makes it clearer; the note appear alongside MEXUM.
Thanks!
I'm not used to that chart format, hopefully I wouldn't have missed it but I certainly might have.
Originally Posted by
Willie Nelson
As the facts in this case are yet to be revealed I cannot comment specifically on what happened to the A380 however, what I can say regarding any type of GNSS approach (RNAV-Z or RNP-AR) is that you must not arm the approach pushbutton unless the ATC assigned altitude and the IAF (or suitable Direct to waypoint) altitude are the same, otherwise the FMGC switches from NAV to FINAL APP mode and therefore will drop down to the NEXT altitude constraint as per the FMGC constraints, thereby bypassing the relevant safe altitude even if it is still selected in the FCU.
This was why, some time back Airservices changed the terminology to "when established cleared Runway xx x approach" that is to say:established on the approach itself and not simply tracking to intercept a waypoint on the approach.
One possible way down the primrose path would be if they had one of the approach transitions from the side loaded, got vectors to a long final instead and saw that they could go to MEXUN without reselecting the approach since it was already in the box and the rest of the approach is the same for all the transitions. Unfortunately, the 3000 feet restriction at SUDOS would not be seen by the FMGC.
It will be interesting to see whether they were cleared for the approach out over the water and selected approach mode too soon with a missing waypoint constraint.