Wheeler AAF comprises approximately 1389 acres of land adjacent to Schofield Barracks and is home to a variety of Department of Defense activities including the Defense Information Systems Agency (DISA), the 169th Aircraft Control & Warning Squadron (169 ACWS) of the Hawaii Air National Guard, the 193rd Aviation Regiment (Medium Lift), Detachment 55 Operational Support Airlift (Det 55 OSA) of the Hawaii Army National Guard, the Regular Army's 25th Infantry Division's 25th Combat Aviation Brigade composed of the 25th Aviation Regiment, the 2nd Sqaudron-6th Cavalry Regiment, and the 209th Aviation Support Battalion, also located on wheeler is the Trial Defense Service-Hawaii.