In July 1962, Sikorsky's proposal, which was essentially a scaled-up S-61R fitted with twin General Electric T64 turboshaft engines and the dynamic systems of the S-64/CH-54, was selected.

The first combat use of the type occurred during the following year when it was deployed to the Vietnamese theater; the CH-53 quickly proved its value for moving heavy payloads, particularly in the recovery of damaged aircraft.

The United States Air Force introduced the HH-53 "Super Jolly Green Giant", configured for special operations and combat search and rescue (CSAR) missions, during the latter part of the Vietnam War; the majority of these were subsequently rebuilt into the MH-53 Pave Low.

Furthermore, many early-build CH-53s were refitted with more powerful engines, while others were reconfigured for different mission roles, such as US presidential flights, training, and airborne mine countermeasures (AMCM) operations.

The heavily upgraded Jolly Green Giant and Pave Low versions of the CH-53 were retired by 2008, flown by the U.S. Air Force for combat search and rescue.

On 27 January 1961, the USMC began working with the U.S. Army, Navy, and Air Force on the "Tri-Service VTOL transport", which would eventually emerge as the LTV XC-142 tiltwing.

[3] In March 1962, the United States Navy's Bureau of Naval Weapons, acting on behalf of the USMC, issued a request for a "Heavy Helicopter Experimental / HH(X)".

[2] The specifications dictated a load capability of 8,000 pounds (3,600 kg) with an operational radius of 100 nautical miles (190 km; 120 mi) at a speed of 150 knots (280 km/h; 170 mph).

It was also specified to possess a higher top speed and greater lifting capacity than existing helicopters while also having a lower empty weight than preceding designs as well.

[3] During July 1962, it was announced that Sikorsky's bid had been selected as the winner on account of various considerations, including cost, technical factors, and production capability.

Military officials favorably received the company's proposed reduction; in September 1962, Sikorsky was awarded a $9,965,635 (~$76.9 million in 2023) contract for the production of a pair of YCH-53A prototypes, as well as a mockup and a ground-test airframe.

Flight trials went more smoothly than expected, helping make up for the time lost in development; on 19 November 1964, the type was formally introduced to the general public.

[7] Heavy lifting in tropical climates demanded more power, so the USMC decided to acquire an improved variant, the CH-53D, with uprated engines, originally the T64-GE-412 then later the T64-GE-413.

[2] Access to the main cabin is via the large passenger door on the right side of the fuselage behind the cockpit, as well as by a power-operated loading ramp to the rear.

While the Sea Stallion's fuselage is watertight, the helicopter is not intended for amphibious use and its ability to land on water is meant to only be used in emergency situations.

[4] While the Sea Stallion's dynamic systems were largely derived from those used on the earlier Sikorsky S-64 Skycrane, substantial reengineering were also involved due to the vastly different operating requirements.

The CH-53D served alongside the CH-53A through the latter portion of the US's presence in Vietnam; both types played a critical role at the end of the conflict, performing evacuations of personnel during Operation Frequent Wind.

[9][8][10] Marine-flown Navy Sea Stallions were the rotary-wing element of Operation Eagle Claw, the attempted rescue of American hostages in Iran in 1980 that ended in disaster and embarrassment at "Desert One".

[20] In August 1968, an Israeli Air Force (IAF) delegation visited Sikorsky's Connecticut plant while seeking information to select the service's next assault helicopter.

[21] The delegation was looking for a helicopter with augmented payload carry capacity, highly maneuverable and robust, that could survive direct hits from different caliber projectiles.

They examined Boeing's CH-47 Chinook and Sikorsky's CH-53, it was recognised that the latter was both larger and stronger than any of the IAF's other helicopters, and thus represented a major advancement in terms of capability.

[citation needed] In 1969, during the War of Attrition, IAF CH-53s landed in Egypt and conveyed a captured Soviet advanced radar system back to Israel for examination by Israeli scientists and engineers (see Operation Rooster 53).

[22] The Yas'ur was also used in various other capacities during the conflict, including the retrieval of a navigator from a downed IAF F-4 Phantom II under sustained enemy fire on 30 June 1970.

Since 1973, Yas'urs have also been used by the IDF to land and extract Sayeret commandos on raids and patrols deep behind enemy lines in Lebanon Syria and the greater Middle East.

On 8 November 1992, a pair of CH-53s performed one of the IAF's longest-distance sea rescue operations to retrieve passenger from the distressed yacht Fantasy 2 off the coast of Sudan.

[25][26] On 16 August 2012, the IAF temporarily grounded its CH-53 fleet following one having experienced in-flight difficulties that led to an emergency landing; initial reports state the issue was related to the rotor blades.

[27] The fleet was again grounded for three weeks after a CH-53 was destroyed by a fire during a training exercise; the IAF subsequently attributed this loss to a defective component and blamed Lockheed Martin for failing to communicate the issue.

[40] The first German-built CH-53G Mittlerer Transporthubschrauber helicopter flew from Speyer on 11 October 1971 and was delivered to the Erprobungsstelle der Bundeswehr 61 flight test center at Manching on 1 December 1971.

[citation needed] To meet ever more demanding specifications, over time the CH-53G received modifications from 1990 designed to improve its service life and operational capabilities.

[citation needed] German Army Aviation Corps units have carried out a wide range of international missions under the auspices of NATO and the UN, providing transport for members of UNSCOM in Iraq, serving in Kosovo with KFOR, with IFOR in Bosnia and Herzegovina, and more recently with ISAF in Afghanistan.