In the late 1950s the Air Force determined that there was a need for a new aircraft to support the "DEW Line" early-warning radar sites located on the far northern ice cap. Testing proved that the C-130 could be easily adapted to this job. A total of twelve ski-equipped C-130Ds were built in 1958. The ski/wheel landing gear allowed the planes to operate from either a normal runway or from ice and snow. Markings shown: 109th Tactical Airlift Group, New York ANG, Schenectady County Airport, New York, 1984