CDU/FMC keyboard

[nimsu1987]

Hi guys, I just noticed that 4 keys on a 747-400 CDU/FMC computer (E N S W) have a white box around them to highlight them (I assume).

I just wondered if any airline pilots could enlighten me as to why. I've looked over google and here and couldn't find any answers. Many thanks

Nim

[500 above]

North
South
East
West

E.G

The alpha characters "N", "E", "W", and "S" indicate positions within the Northern or Southern hemisphere for latitude, and the western or eastern hemisphere for longitude:
"N" = north latitude / west longitude
"E" = north latitude / east longitude
"W"= south latitude / west longitude
"S" = south latitude / east longitude

You could google ARINC 424 for FMS lat/long data entry.

[rennaps]

500
Excuse my ignorance but is that an over-ride to what is in the database coding or is that for manually entering way-points?

[500 above]

Hi

With most airlines, the FPL would usually be 'sent' to the FMS and checked then accepted by the crews. Some operators (smaller operators and some biz-jet operators) will manually enter data. NAT tracks would not be in any database due to the fact that they change daily due to the fact that the weather changes - namely the jetstream.

So, in a word, yes, it's for manual entry of waypoints in AIRINC 424 format, not just for flying the tracks or random routes either, but mostly this is where it would be utilised.

More gen for you:

RAC - 11.0 NORTH ATLANTIC OPERATIONS - Transport Canada

Section 11.4 of the above should fill the gaps.

[nimsu1987]

Fantastic, thanks for the replies! I'm usually pretty hot on acronyms so that's pretty embarrassing I didn't manage to link those two together. Thanks for the detailed info too. Very interesting. Take care.