Between June 29 and Aug. 3 of this year, the United States and 21 other nations participated in Rim of the Pacific Exercise, or RIMPAC. The worlds largest international maritime exercise, the RIMPAC series began in 1971. Exercises now take place every other year in and around the Hawaiian Islands and off the West Coast of the United States.

RIMPAC 2012 was the largest ever planned, and this year the exercise provided a unique opportunity for more than 42 naval ships and submarines, 200 military aircraft and 25,000 personnel to participate in joint maneuvers training. RIMPAC helps participating forces establish and maintain cooperative relationships that are critical to ensuring the safety and security of sea lanes the world over. RIMPAC also promotes stability in the Pacific region, with benefits to all participating nations.

This years RIMPAC anti-mine countermeasure missions were conducted off the coast of San Diego, Calif. and included ships from multiple navies. Also participating in a forward operating capacity was a detachment of U.S. Navy Sikorsky MH-53E Sea Dragon helicopters from Helicopter Mine Countermeasures Squadron 14 (HM-14) Vanguard, which conducted airborne mine countermeasures (AMCM) missions.

The MH-53E is the largest helicopter in the U.S. Naval inventory and a very capable answer to the worldwide mine warfare threat. For close to 25 years, the 73,500-pound MH-53E Sea Dragons with their 21,000-pound fuel loads have been a proven solution to the long endurance needed during mine countermeasures missions. The MH-53E has longest unrefueled endurance of any helicopter in the fleet, capable of up to five hours of flight time. It can also carry an aerial refueling probe, giving it virtually unlimited range, huge mission flexibility and the ability to self-deploy.

To participate RIMPAC, two HM-14 Sea Dragons flew cross-country in late June from their home base of Naval Air Station Norfolk in Norfolk, Va. to Naval Air Station North Island in Coronado, Calif. The MH-53Es took four days to make the journey, with stops in Nashville, Tenn. and Lubbock, Texas (a planned aerial refueling session using a United States Marine Corps Lockheed-Martin KC-130 aircraft was canceled due to scheduling problems). The helicopters arrived in California on July 3. 

Mine warfare is a real and continuously evolving threat. While mines and mine warfare threaten the U.S. Navy and its allies around the world, at the present time, the danger is particularly severe in the Persian Gulf region. An inexpensive and effective weapon, mines can be deployed in mass numbers quickly, over large areas and with little skill required of the enemy deploying them. Mines also pose a serious threat to civilian ships and commercial shipping traffic, in addition to threatening allied forces.

The process of clearing a minefield is called mine countermeasures. It is a complicated, expensive and dangerous process that is demanding in terms of both manpower and equipment.

The existence of U.S. Navy airborne mine countermeasures is not well known or understood by the American public.  In fact, AMCM is performed by only two Navy MH-53 squadrons: HM-14 and HM-15, both of which are based in Norfolk. The squadrons are capable of operating from either shore bases or from those Navy ships that are able to accommodate larger helicopters, normally amphibious assault ships that also have enough room for the substantial amount of mission and support equipment and personnel that the missions require.

Once deployed, a squadron or detachment will arrive to the operational area, set up shop and get to work. There are different techniques for AMCM but most consist of low-altitude, low-speed operations, so flight crews appreciate the power and redundancy of the MH-53Es three engines. When operations begin, different mission equipment devices are towed behind the helicopter in order to neutralize mine fields. While towing these devices, the MH-53 Sea Dragon is capable of cutting mines from their moorings or of activating mines by creating magnetic, acoustic or seismic signatures mimicking shipping traffic.

The devices under tow have different capabilities and are selected based on intelligence indicating the type of mine threat. Indeed, local intelligence is a massive part of the mine-hunting equation. Having a clear and thorough understanding of the enemys capabilities and techniques can make the hunt for mines much easier, and more importantly timelier and more efficient.

During the war game portion of RIMPAC 2012, HM-14 was given an opportunity to execute its primary mission of AMCM. The exercise pitted a multinational force consisting of the U.S. and its allies against a fictional aggressor enemy nation. For the exercise, HM-14 used two AMCM devices, the MK-103 and the Q-24. The MK-103 is a mechanical minesweeping device that uses explosive cutters to sever tethered mines from their moorings. In the RIMPAC exercise, once the mines were cut with the MK-103, they were allowed to come to the surface. A second MH-53E then deployed explosive ordnance disposal (EOD) divers into the minefield in what were called pouncer operations. This entailed the helicopter coming in at a low airspeed and altitude (10 feet and 10 knots) and casting the divers from the aircraft. The divers would then proceed to neutralize the mines.

The second device used in the exercise, the Q-24, uses internal sonar and laser assemblies to produces images that detect, classify and localize mines. The device deploys quickly and produces very detailed images. An added benefit of the Q-24 is that it does not require a diver to identify a mine, thus keeping the EOD teams at a safe distance. During the RIMPAC exercise a total of approximately 50 mine-like contacts were identified using the Q-24. These contacts were prosecuted using EOD divers and live cutting exercises. The missions were successful, and the waters in question were made clear for the fictional invasion ground forces to reach their beach objectives.

During RIMPAC 2012, the Sea Dragons missions were not limited to AMCM they also included the types of missions requested of the MH-53E in the real world, such as vertical on-board delivery (VOD), heavy lifts of supplies and downed aircraft, and troop transport for regular and special operations forces. RIMPAC 2012 reinforced how the aircrafts large internal cabin capacity and exceptional range make it an extremely capable and highly regarded asset in the Naval fleet.

During HM-14s 40-day west coast deployment, 251 hours were flown, 70 sorties were completed, and pilot readiness was refined in both the AMCM and mountain flying regimes. The detachment even transported a dolphin from the Navys Marine Mammal Program! Overall, RIMPAC 2012 turned out to be a success for HM-14 and for the U.S. Navy as a whole.

The MH-53E is scheduled to be decommissioned in 2026, and at this time it does not have a designated replacement. That said, the Sikorsky CH-53K a successor with a massive increase in power and capability that is currently in development looks to be coming around at just the right time. The future will tell how the U.S. Navys AMCM mission evolves in response to this continuously evolving threat.