This is a (not very good) font designed to emulate the experience of a dot-matrix display; these displays are found on trains, buses, etc. This font supports most characters up to Latin-1 Supplement, and full Unicode support is on the way.
Font Airport is an interpretation of the information displays found in, well, airports and by maintaining a set matrix, a few oddities emerge.
The lower case is a negative of the UPPER CASE to allow you to combine the full matrix, in two tones, if you like.
If you do decide to download Font Airport, we'd be chuffed if you emailed us images of it in use, thanks.