Test team aims at new machine gun for Pave Hawk

by Rebecca Amber
412th Test Wing Public Affairs

1/12/2016 - EDWARDS AIR FORCE BASE, Calif.  -- Arriving in the rain, an Air Force HH-60G Pave Hawk helicopter landed at Edwards Jan. 5, 2016, to begin testing the ballistic dispersion of a GAU-21 .50 caliber machine gun.

The Pave Hawk will be here until Jan. 22 with the 412th Test Wing and 418th Flight Test Squadron providing the facilities, range safety, photographic documentation and maintenance support equipment.

The 96th Test Wing at Eglin Air Force Base, Florida, and the 412th Test Wing partnered up to provide the 413th Flight Test Squadron, Detachment 1 from Nellis Air Force Base, Nevada, a location for their test team to accomplish baseline ballistics testing. That location is Edwards AFB's Gun Harmonizing Range.

The testing is part of Air Combat Command's "HH-60 Defensive Weapons System Upgrade" modification proposal.

The modification proposal requires the new weapon to be an open bolt system, have a longer barrel life, a higher cyclic rate of fire, be lighter weight and have reduced recoil. The selected weapon must also be used currently by other Department of Defense services.

According to James Cooley, 413th Flight Test Squadron Det. 1 technical director, the closed-bolt GAU-18 defensive system, which has been used on the HH-60, has demonstrated a short barrel life (3,000 rounds), relatively low cyclic rate of fire (550 rounds per minute), high recoil and is vulnerable to unsafe ammunition "cook-offs."

The FN Herstal M3M, designated the GAU-21, is an open bolt system with a barrel life of 10,000 rounds, a cyclic rate of fire of up to 1100 rounds per minute, and reduced recoil over standard .50 caliber weapons due to the use of a soft mount.

As a proven weapon system, the current test effort is focused on integrating the GAU-21 into the HH-60G weapon platform using the Gun Mount/Ammunition Handling System, which was designed for the Air Force by the U.S. Navy.

The objective of this test effort is to evaluate the ballistic dispersion of the GAU-21 .50 caliber machine gun mounted to the HH-60G via the GAU-21 GM/AHS when operated in the fixed forward fire and fixed side fire modes.

The Pave Hawk, a variant of the UH-60 Blackhawk used by the Army, is stationed at Nellis Air Force Base, Nevada. Its primary objective is Combat Search and Rescue. The combat crew of four includes the pilot, copilot and two special mission aviators as well as three Air Force pararescue men for rescue operations.

The Combat Search and Rescue Combined Test Force located at Nellis AFB is comprised of 413th FLTS Det. 1 and the 96th Test Wing, which fall under Air Force Materiel Command, and conducts developmental testing. Air Combat Command's 88th Test and Evaluation Squadron and 53rd Test Wing, also at Nellis, conduct operational testing.

The 823rd Maintenance Squadron is also providing aircraft and weapons maintenance support.

The Pave Hawk differs from the Blackhawk in its auxiliary fuel tanks, aerial refueling probe and forward-looking infrared. It also has a color weather radar, integrated electronic warfare suite, external gun mount and ammunition handling system as well as an integrated navigation suite.