The Sikorsky MH-60G/HH-60G Pave Hawk is a four-blade, twin-engine, medium-lift utility military helicopter manufactured by Sikorsky Aircraft. It is a derivative of the UH-60 Black Hawk and incorporates the US Air Force PAVE electronic systems program. The HH-60/MH-60 is a member of the Sikorsky S-70 family. The MH-60G Pave Hawk's primary mission is insertion and recovery of special operations personnel, while the HH-60G Pave Hawk's core mission is recovery of personnel under hostile conditions, including combat search and rescue. Both versions conduct day or night operations into hostile environments. Because of its versatility, the HH-60G may also perform peacetime operations such as civil search and rescue, emergency aeromedical evacuation (MEDEVAC), disaster relief, international aid and counter-drug activities. Design and development In 1981, the U.S. Air Force chose the UH-60A Black Hawk to replace its HH-3E Jolly Green Giant helicopters. After acquiring some UH-60s, the Air Force began upgrading each with an air refueling probe and additional fuel tanks in the cabin. The machine guns were changed from 7.62 mm (0.308 in) M60s to .50 caliber (12.7 mm) XM218s. These helicopters were referred to as "Credible Hawks" and entered service in 1987. Afterwards, the Credible Hawks and new UH-60As were upgraded and designated MH-60G Pave Hawk. These upgrades were to be done in a two-step process. However, funding allowed only 16 Credible Hawks to receive the second step equipment. These helicopters were allocated to special operations use. The remaining 82 Credible Hawks received the first step upgrade equipment and were used for combat search and rescue. In 1991, these search and rescue Pave Hawks were redesignated HH-60G. The Pave Hawk is a highly modified version of the Sikorsky UH-60 Black Hawk. It features an upgraded communications and navigation suite that includes an integrated inertial navigation/global positioning/Doppler navigation systems, satellite communications, secure voice, and Have Quick communications. The term PAVE stands for Precision Avionics Vectoring Equipment. All HH-60Gs have an automatic flight control system, night vision goggles lighting and forward looking infrared system that greatly enhances night low-level operations. Additionally, some Pave Hawks have color weather radar and an engine/rotor blade anti-ice system that gives the HH-60G an all-weather capability. Pave Hawk mission equipment includes a retractable in-flight refueling probe, internal auxiliary fuel tanks, two crew-served (or pilot-controlled) 7.62 mm miniguns or .50-caliber machine guns and an 8,000 pound (3,600 kg) capacity cargo hook. To improve air transportability and shipboard operations, all