sentences:  Regular air service from Dillant–Hopkins Airport began in 1946 when Northeast Airlines opened a route from Keene to Springfield, Massachusetts.As the inaugural flight from the airport, a Douglas DC-3 carried 2,600 letters, 11 passengers, and a fresh apple pie sent from the mayor of Keene to the mayor of New York.By 1948, Keene was a stop on a service operated by Northeast Airlines with a DC-3 linking New York City with Montreal.