The RD-53 Sea Stallion is designed for both land and ship operations. The primary mission is vertical assault transport of equipment and supplies. The aircraft has an external cargo hook rated up to 20,000 pounds and it can carry palletized cargo and vehicles internally. The secondary mission of the Sea Stallion is vertical assault transport of personnel. It is capable of seating 55 combat loaded Marines or carrying 24 litters. It is equipped with an aerial refueling probe and can be refueled while airborne from a KC- 130 tanker. Sikorsky manufactured the RH-53 from 1971 to 1973 for the US Navy as a mine countermeasures aircraft. The Marines took possession of the RH-53D from the Navy in the early 1970’s.

From the 34th aircraft, all CH-53s were fitted with hardpoints for the towing of mine countermeasures equipment. However the use of such equipment required a greater level of power than was generally available. Consequently, the US Navy re-engined 15 aircraft with the T64-GE-413 powerplant, and added rearview mirrors on tube mounts either side of the nose. Designated RH-53A, these served with HM- 12, but were subsequently demodified back to CH-53A status. Some Marine CH-53Ds have been used in the mine-hunting role. Aiding this application was the adoption of the definitive RH-53D variant, which introduced T64-GE-415 engines of greater power and the option to mount a refueling probe and sponson tanks. The mine countermeasures equipment is towed behind the aircraft from a heavy trapeze attached to the rear ramp and rear fuselage. Optional equipment includes various floating sleds to handle contact, acoustic and magnetic mines. The SPU-1 Magnetic Orange Pipe system is used against shallow-water mines. Mines brought to the surface by the system are detonated by using a pair of 50 cal machine guns.