Those radar codes were based off the airports in the city - those codes you are mentioning are used by the FAA to identify airports. They have some clever stories behind them.
ORD - Original name of the airport when it was a military field in the Chicago suburb of "
Orchard Place."
BNA - Nashville airport. The "NA" stands for Nashville. The "B" stands for Berry, the last name of
Harry Berry, the head of the Tennessee Works Progress Administration during the 1930s.
MCO - Orlando International Airport. MCO stands for "
McCoy," the name of the old air force base in the same general location of the airfield.
MSY - I will let a news article tell the story of New Orleans:
MSY: Last, and certainly the best airport code story of all is the three letter code designation of the Louis Armstrong New Orleans International Airport. On the last day of 1910, John Moisant, the first person to build and fly a plane with an all metal frame, and the first pilot to fly over the English Channel with a passenger and an animal, died of a broken neck after he was thrown out of his nose-diving aircraft at the current location of New Orleans’ major airport.
Stock yards for cattle were later put on the land where Moisant met his fate. The owners wanted to honor John Moisant, so they called the stock yards the Moisant Stock Yards, or MSY for short.
The city of New Orleans later bought the stock yards for airfield construction and named the completed project Moisant Field. In 1962, Moisant Field was renamed New Orleans International Airport, but the stock yards’ designation still remains to this very day.
