The Sikorsky CH-53E Super Stallion is a heavy-lift helicopter operated by the United States military. As the Sikorsky S-80, it was developed from the CH-53 Sea Stallion, mainly by adding a third engine, adding a seventh blade to the main rotor, and canting the tail rotor 20°. It was built by Sikorsky Aircraft for the United States Marine Corps. The less common MH-53E Sea Dragon fills the United States Navy's need for long-range minesweeping or airborne mine countermeasures missions, and performs heavy-lift duties for the Navy. The Sikorsky CH-53K King Stallion, which has new engines, new composite rotor blades, and a wider aircraft cabin, is set to replace the CH-53E.
Development
Background
The CH-53 was the product of the U.S. Marines' "Heavy Helicopter Experimental" (HH(X)) competition began in 1962. Sikorsky's S-65 was selected over Boeing Vertol's modified CH-47 Chinook version. The prototype YCH-53A first flew on 14 October 1964. The helicopter was designated "CH-53A Sea Stallion" and delivery of production helicopters began in 1966. The first CH-53As were powered by two General Electric T64-GE-6 turboshaft engines with 2,850 shp (2,125 kW) and had a maximum gross weight of 46,000 lb (20,865 kg), including 20,000 lb (9,072 kg) in the payload.
Variants of the original CH-53A Sea Stallion include the RH-53A/D, HH-53B/C, CH-53D, CH-53G, and MH-53H/J/M. The RH-53A and RH-53D were used by the US Navy for minesweeping. The CH-53D included a more powerful version of the General Electric T64 engine, used in all H-53 variants, and external fuel tanks. The CH-53G was a version of the CH-53D produced in West Germany for the German Army.
The U.S. Air Force's HH-53B/C "Super Jolly Green Giant" was for special operations and combat rescue, and was first deployed during the Vietnam War. The Air Force's MH-53H/J/M Pave Low helicopters were the last of the twin-engined H-53s and were equipped with extensive avionics upgrades for all-weather operation.
H-53E
In October 1967, the US Marine Corps issued a requirement for a helicopter with a lifting capacity 1.8 times that of the CH-53D that would fit on amphibious warfare ships. The US Navy and US Army were also seeking similar helicopters at the time. Before the issue of the requirement, Sikorsky had been working on an enhancement to the CH-53D, under the company designation "S-80", featuring a third turboshaft engine and a more powerful rotor system. Sikorsky proposed the S-80 design to the Marines in 1968. The Marines liked the idea, since it promised to deliver a good solution quickly, and funded the development of a testbed helicopter for evaluation.
In 1970, against pressure by the US Defense Secretary to take the Boeing Vertol XCH-62 being developed for the Army, the Navy and Marines were able to show the Army's helicopter was too large to operate on landing ships and were allowed to pursue their helicopter. Prototype testing investigated the addition of a third engine and a larger rotor system with a seventh blade in the early 1970s. In 1974, the initial YCH-53E first flew.
Changes on the CH-53E also include a stronger transmission and a fuselage stretched . The main rotor blades were changed to a titanium-fiberglass composite. The tail configuration was also changed. The low-mounted, symmetrical, horizontal tail was replaced by a larger, vertical tail, and the tail rotor tilted from the vertical to provide some lift in hover while counteracting the main rotor torque. Also added was a new automatic flight control system. The digital flight control system prevented the pilot from overstressing the aircraft.
YCH-53E testing showed that it could lift 17.8 tons (to a wheel height), and without an external load, could reach at a 56,000-pound gross weight. This led to two preproduction aircraft and a static test article being ordered. At this time, the tail was redesigned to include a high-mounted, horizontal surface opposite the rotor with an inboard section perpendicular to the tail rotor then at the strut connection cants 20° to horizontal. This helps with a tilt at high speed.
The initial production contract was awarded in 1978, and service introduction followed in February 1981. The first production CH-53E flew in December 1980. The US Navy acquired the CH-53E in small numbers for shipboard resupply. The Marines and Navy acquired a total of 177.