CH-53 Sea Stallion

The Sikorsky CH-53 Sea Stallion (company designation S-65) is a twin-engine heavy-lift transport helicopter built by Sikorsky Aircraft in the United States for the US Marine Corps, which received its first production aircraft on 12 September 1966 and flew the type in combat from January 1967 until February 2012. Designed to a March 1962 Navy requirement to replace the CH-37 Mojave, it combined a scaled-up S-61R fuselage with the dynamic system of the S-64 Skycrane and two General Electric T64 turboshafts. Israel and Germany still flew the type in the 2020s. The three-engine CH-53E Super Stallion and the CH-53K King Stallion are later developments covered separately.

Development

The Marine Corps began seeking a replacement for its piston-engined HR2S (CH-37) in 1960. In March 1962 the Navy's Bureau of Naval Weapons issued the Heavy Helicopter Experimental, HH(X), requirement on the Marines' behalf: a 3,600 kg (8,000 lb) payload over a 190 km (100 nmi) radius at 280 km/h (150 kn), for assault transport, aircraft recovery, troop lift and medical evacuation. Boeing Vertol offered a modified CH-47 Chinook, Kaman a development of the Fairey Rotodyne, and Sikorsky the S-65. Sikorsky won in July 1962 on cost, technical factors and production capacity, and in September 1962 received a $9,965,635 contract for two YCH-53A prototypes, a mockup and a ground-test airframe, having offered to develop the type with two prototypes instead of four.

The first YCH-53A flew at Stratford, Connecticut, on 14 October 1964, four months late, after an initial production contract for 16 aircraft had been placed that September; deliveries to an operational unit began in September 1966. The CH-53A reached Vietnam in January 1967. Production ran to 141 CH-53As including the prototypes. The Air Force ordered the HH-53B in September 1966, flown in March 1967 with a refuelling probe, drop tanks, a rescue hoist and T64-GE-3 engines, followed by the better-armoured HH-53C and the CH-53C transport without a probe. For heavy lifting in tropical heat the Marines adopted the CH-53D, first flown in January 1969, with T64-GE-412 and then T64-GE-413 engines, an uprated transmission and seating for 55 troops; 126 were built. The Navy converted 15 CH-53As to RH-53A minesweepers in 1971 and received 30 RH-53Ds from 1973. The CH-53E added a third engine and displaced the Sea Stallion in the Marine heavy-lift role, and the CH-53K is replacing the CH-53E.

Design

The CH-53A carried a crew of four and up to 38 equipped troops, 24 litters with attendants, 3,600 kg (8,000 lb) internally or 5,900 kg (13,000 lb) on a single-point sling hook. A power-operated rear ramp allows drive-on loading. The watertight fuselage is a larger development of the S-61R's; all fuel is housed in the two sponsons, and the tail boom and rotor blades fold automatically for shipboard stowage. Mechanical flight controls are backed by three independent hydraulic systems, and crew and essential systems are armoured. The fully articulated six-blade main rotor spans 22.02 m (72 ft 3 in) and is paired with a four-blade tail rotor; titanium is used in fatigue-prone dynamic components, and later CH-53Ds introduced nitrogen-pressurised blades whose tip indicators reveal cracks.

The first T64-6 engines, mounted on the upper fuselage, gave 2,850 shp (2,130 kW) each, and the CH-53D's T64-GE-412 and T64-GE-413 3,695 shp (2,755 kW) and 3,925 shp (2,927 kW). The CH-53D's fuselage is 20.57 m (67 ft 6 in) long and 8.64 m (28 ft 4 in) wide over the sponsons; it weighs 10,717 kg (23,628 lb) empty and 19,051 kg (42,000 lb) at maximum take-off, has a maximum speed of 315 km/h (170 kn), a range of 1,000 km (540 nmi) and a service ceiling of 5,110 m (16,750 ft). German CH-53Gs gained missile warning and self-protection systems, two external tanks for a range of 1,770 km (1,100 mi) with 36 troops or 5,500 kg (12,100 lb), and a night-vision-goggle cockpit by early 2001; the 20 CH-53GS received T64-100 engines for Afghanistan and 40 CH-53GAs a new flight deck, autopilot and FLIR from 2010.

Armament

The CH-53A mounted a 7.62 mm M60 machine gun in each side door and the CH-53D two 12.7 mm M2/XM218 guns; later Marine aircraft carried door-mounted 12.7 mm GAU-15/A guns and some a ramp-mounted GAU-21. German CH-53Gs carry two 7.62 mm MG3s in the doors, being replaced by 12.7 mm M3M/GAU-21s in the doors and on the ramp. The RH-53D's two 12.7 mm Brownings were fitted to detonate swept mines; its cargo hook was rated at 11,340 kg (25,000 lb).

Operational History

Marine CH-53As and CH-53Ds recovered downed aircraft and evacuated personnel throughout the Vietnam War and flew the evacuation of Saigon in Operation Frequent Wind on 29–30 April 1975. Air Force HH-53s were the primary search-and-rescue helicopter in Southeast Asia from 1967 to 1975 and inserted the Son Tay raiders in Operation Ivory Coast in 1970; HH-53s and CH-53Cs carried the assault force in the Mayagüez incident, in which three CH-53s of the 21st Special Operations Squadron were shot down on 15 May 1975. Marine-flown Navy RH-53Ds formed the rotary-wing element of Operation Eagle Claw in April 1980; six were lost at Desert One and five were abandoned and taken over by Iran, joining six sold to Iran in the 1970s. Marine CH-53s took part in Grenada in 1983 and in Iraq and Afghanistan, where the CH-53D flew its last missions in February 2012; HMH-362 retired the last CH-53Ds in August 2012 and stood down that November, the MV-22B having taken over the CH-53D's roles.

Israel chose the CH-53 over the Chinook in 1968 and took delivery of its first S-65C-3 on 2 October 1969, with 35 more following the initial seven. Named Yas'ur, the type flew in the War of Attrition from delivery, carried a captured Soviet radar out of Egypt in Operation Rooster 53 in 1969, and was upgraded by Israel Aircraft Industries and Elbit between the 1980s and 1997 and again to Yas'ur 2025 standard by 2015. One was shot down by an anti-tank missile in the 2006 Lebanon War, killing five crew, and on 7 October 2023 a Yas'ur carrying about 50 paratroopers was hit by a Hamas anti-tank missile, reportedly a Kornet; it landed in an open field, the occupants got out with minor to moderate injuries, and a second missile destroyed it on the ground. Israel operated 21 as of November 2023 and selected the CH-53K as replacement in February 2021. Germany evaluated the type in 1966 and ordered 110 CH-53Gs in June 1968; after two Sikorsky-built pre-production aircraft in 1969, VFW-Fokker assembled and licence-built the production aircraft at Speyer, delivering them between 1971 and 1975; the fleet served with UNSCOM in Iraq, IFOR, KFOR and ISAF, passed from the Army to the Luftwaffe's Helicopter Wing 64 in January 2013, and is to be replaced by 60 CH-47Fs under a 2022 decision. Austria's two S-65Ö, flown on Alpine rescue from 1970, went to Israel in 1981, and Mexico's four ex-Israeli CH-53Ds, bought in 2003, were withdrawn by 2013.

Variants

• CH-53A: Initial Marine Corps transport with T64-GE-6 engines; 139 production aircraft plus two YCH-53A prototypes.
• HH-53B/C: Air Force combat search-and-rescue versions with refuelling probe, hoist and drop tanks, most later rebuilt as MH-53 Pave Lows.
• CH-53D: Marine variant with T64-GE-412/413 engines, uprated transmission and 55-troop cabin; 126 built, retired in 2012.
• RH-53D: Navy airborne mine-countermeasures variant with 12.7 mm guns and refuelling provision; 30 built plus six for Iran.
• CH-53G: German CH-53D derivative built by VFW-Fokker, upgraded as CH-53GS, GE and GA; 110 ordered.
• S-65C-3 Yas'ur: Israeli CH-53D export version, upgraded to Yas'ur 2000 and Yas'ur 2025 standards.
• CH-53E Super Stallion: Three-engine heavy-lift development (S-80E) that replaced the Sea Stallion in the Marine heavy-lift role, itself being succeeded by the CH-53K.