Originally Posted by cha-cha-cha

air at the end (example: Korean air)

means coach class will be uncomfortable.

air at the beginning (example: Air france)

means coach class will be unpleasant.

airlines (example: United airlines)

means coach class will not be comfortable.

air lines (example: Delta air lines)

means coach class will not be pleasant.

airways (example: British airways)

means coach class will be a drag.