The Sikorsky HH-60D Nighthawk was developed as a CSAR (Combat Search and Rescue) helicopter for the US Air Force based on the US Army's UH-60A Blackhawk. 

The HH-60D, which is tasked with independent rescue operations in combat zones, is different from conventional combat rescue helicopters in that it can rescue friendly pilots in all weather conditions without friendly escorts. For this reason, it can be equipped with air-to-ground and air-to-air missiles, machine guns, etc. as self-defense weapons . In addition, it is equipped with an aerial refueling system, large fuel tanks, infrared night vision equipment, and terrain following/obstacle avoidance radar.