'Ldg Alt ' logo on NG - what is it for ?

[kotakota]

Occasionally after landing , to the right of the QNH appears the
message 'Ldg Alt' ( Amber )
Cannot be found anywhere in our Boeing manuals , even by our own little boffins.
Any ideas ? i want to put it up for our next Tech questionnaire !!

[regor]

The 'LDG ALT' message you are referring to is a failure flag which will be displayed if there is no valid FMC landing altitude for either the departure runway or destination runway.

Under normal circumstances, with a valid departure/destination airfield & rwy in the FMC, the landing altitude is displayed on the altitude bar as a cross-hatched area in amber. If this data is missing or invalid then the 'LDG ALT' flag will be displayed instead of the cross hatched area.

If you are seeing this after landing, this will be due to the FMC dumping the route after touchdown.

This is definately in our OPS manual, Vol. 2 Systems reference chapter 10.11.xx

Hope this clears up the mystery!

[kotakota]

Thanks regor , I thought it might be Database territory. Your very lucid explanation will be winging its way to the bod i/c of manual content !!
Unusually , it does not even appear in the 737 handbooks from Transair so beloved of our new wannabees, which are normally very good for detail often missing from manuals.