The 135th AS is the group's flying component and has operated the C-130E since 1990. The unit was activated in September 1955 as the 135th Air Resupply Squadron at Harbor Field, Baltimore with C-46Ds and SA-16Bs. Redesignated the 135th Troop Carrier Squadron in October 1958, the unit moved to Glenn L. Martin Airport in April 1960, joining the 135th TCG in January 1962. Shortly afterwards, the unit became an Air Commando Squadron with the U-10 assigned in August 1963, although the Helio Couriers were transferred to South East Asia in August 1965 and replaced by U-6As. Special Operations Squadron status was applied in 1968. The U-10s returned in August 1967, operating alongside the HU-16B until 1971, when the unit became a Tactical Air Support Squadron with the O-2A. The unit's designation changed to Tactical Airlift Squadron in April 1977 with the arrival of the C-7B. The Caribou was replaced by the C-130B in October 1980.