Originally Posted by 747Flyer

YGTBSM -

Let's go through it:

NWA=Northwest Airlines
DAL=Delta Air Lines (no, not Airlines)
BA=British Airways
bmi=British Midlands Airways
LH=Lufthansa
and my personal favorite:
KLM=Koninklijke Luchtvaart Maatschappij, literally Royal Aviation Company; usual English translation: Royal Dutch Airlines)
(there will be a spelling test later)
Now there are lots of others, but:
KAL= Korean Airlines