The Federal Aviation Administration (FAA) gives each commercial airport a three letter designation. Sometimes, they are very obvious, like MSP stands for Minneapolis St. Paul International Airport, PIT stands for Pittsburgh International Airport, HOU stands for the William P Hobby Airport in Houston, TX, LGA signifies LaGuardia Airport in New York, or LAX means Los Angeles International.

Some are odd, but meaningful, as well. For example, the Stevens Point / Wausau, Wisconsin airport code is CWA. This is a result of the airport's full name - Central Wisconsin Airport.

Port Columbus International Airport, however, perplexed me for a long while. It's designation is CMH. There is a television station in town with the call letters WCMH. CMH is used in a variety of different ways around town. At the airport, I discovered the original name of the airport was Columbus Metropolitan Airport. That solved two thirds of the question.

Finally, I discovered the answer. The H in CMH stands for Hangar. CMH is a VERY old designation for the Columbus Metropolitan Hangar that was a hub for commercial cargo and a few passenger routes in the airport's infancy. As the airport grew, the name didn't.

CMH means Columbus Metropolitan Hangar.