HSC-21

Helicopter Sea Combat Squadron 21 (HSC-21), nicknamed "Blackjacks", is an aviation unit of the United States Navy based at Naval Air Station North Island. HSC-21 is made up of five expeditionary detachments that deploy aboard ships including Combat Logistics Force support ships, Hospital Ships and Amphibious Assault ships, among others. HSC-21 flies the Sikorsky MH-60S Seahawk helicopter.

History
HSC-21 was established as Helicopter Combat Support Squadron 11 (HC-11) "Gunbearers" on 1 October 1977 at Naval Air Station North Island, San Diego, California (United States), to provide logistics support for the units of the United States Pacific Fleet. In April 2005, HC-11 was redesignated HSC-21 "Blackjacks". During Operation Iraqi Freedom HSC-21 had shore base detachment as a part of the 2515th Naval Air Ambulance Detachment, Udari Army Airfield, Kuwait. This detachment closed in Fall 2012.