An airport was a location where aeroplanes took off and landed.
On 20 July 1966, the Second Doctor, Polly Wright, Ben Jackson and Jamie McCrimmon encountered Chameleons at Gatwick Airport. (TV: The Faceless Ones)
In 1981, Tegan Jovanka was on her way to Heathrow Airport to begin working as an air stewardess when she inadvertently joined the Fourth Doctor on his travels. (TV: Logopolis) The Fifth Doctor finally returned her to the airport in 1982. (TV: Time-Flight)
Leadworth did not have an airport or a nuclear power station. (TV: The Eleventh Hour)
When Rex Matheson used Central Intelligence Agency resources to bring Gwen Cooper and Jack Harkness to the US during the Miracle Day event, the plane was landed at Washington Dulles International Airport (TV: Rendition)