Martin State Airport (MTN/KMTN) is a joint civil-military public use airport located nine nautical miles east of Baltimore, Maryland, within the census-designated place of Middle River. The Maryland Aviation Administration operates the airport. Historically, the site served as the plant airport for the Glenn L. Martin Company, which produced military aircraft from the 1920s to the 1960s. The Glenn L. Martin Maryland Aviation Museum is located at the southeast corner of the airport. In 1974, the State of Maryland purchased the airport from Martin Marietta for $9.4 million. The military presence at the airport consists of the Maryland Air National Guard's 175th Wing, which is a tenant activity with locally based A-10C aircraft. Their facility is officially named Warfield Air National Guard Base and is situated on the northeast side of the field. Martin State Airport covers 747 acres at an elevation of 6 meters above mean sea level. It features one asphalt-paved runway, designated 15/33, measuring 2,133 by 55 meters. The airport also includes a concrete helipad. As of October 2022, the airport recorded 87,130 aircraft operations annually, with 241 aircraft based there, including 24 military aircraft. The airport supports various general aviation and commercial operators, serving as a base for local news helicopters, Medevac services, and aviation units for the Maryland State Police, Baltimore County Police, and Baltimore City Police. It also hosts flight training activities through three flight schools.