Sikorsky CH-53 Sea Stallion

The CH-53 Sea Stallion is the most common name for the Sikorsky S-65 family of heavy-lift transport helicopters. Originally developed for use by the United States Marine Corps, it is also in service with Germany, Iran, Israel, and Mexico. The United States Air Force operated the HH-53 "Super Jolly Green Giant" during the late- and post-Vietnam War era, updating most of them as the MH-53 Pave Low.

The dimensionally-similar CH-53E Super Stallion is a heavier-lifting, improved version designated S-80E by Sikorsky. Its third engine makes it more powerful than the Sea Stallion, which it has replaced in the heavy-lift mission.

Origins
In 1960, the United States Marine Corps began to seek a replacement for their HR2S piston-powered helicopters. On 27 January 1961, the Marine Corps began working with the other three U.S. armed services on the "Tri-Service VTOL transport", which would eventually emerge as the Vought-Hiller-Ryan XC-142A tiltwing. The design became more elaborate and the program stretched out, causing the Marines to drop out when they decided they would not receive a working machine in a satisfactory timeframe. In the end, the XC-142A, although a very innovative and capable machine, never entered production.

In March 1962, the US Navy's Bureau of Naval Weapons, acting on behalf of the Marines, issued a request for a "Heavy Helicopter Experimental / HH(X)". The specifications dictated a load capability of 8000 lb with an operational radius of 100 nmi at a speed of 150 kn. The HH(X) was to be used in the assault transport, aircraft recovery, personnel transport, and medical evacuation roles. In the assault transport role, it was to be mostly used to haul heavy equipment instead of troops.

In response, Boeing Vertol offered a modified version of the CH-47 Chinook; Kaman Aircraft offered a development of the British Fairey Rotodyne compound helicopter; and Sikorsky offered what amounted to a scaled-up version of the S-61R, with twin General Electric T64 turboshafts and the dynamic system of the S-64, to be designated the "S-65". Kaman's proposal quickly died when the British government dropped its backing of the Rotodyne program. Competition between Boeing Vertol and Sikorsky was intense, with the Chinook having an advantage because it was being acquired by the United States Army. Sikorsky threw everything into the contest and was awarded the contract in July 1962.



The Marines originally wanted to buy four prototypes but ran into funding problems. Sikorsky, determined to keep the deal, cut their estimate for development costs and said that the program could be done with two prototypes. The military bought off on the proposal, and in September 1962 Sikorsky was awarded a contract for a little under US$10 million for two "YCH-53A" prototypes, as well as a mockup and a ground-test airframe.

The development program did not go entirely smoothly, due to a shortage of engineering resources plus various failures of subcontractors and the government, but these problems were gradually overcome. There was also the problem that U.S. Secretary of Defense Robert S. McNamara was pushing to maintain "commonality" between the armed services by using the Chinook, but the Marines managed to convince McNamara's staff that the Chinook could not meet their requirements without numerous expensive changes.

All these obstacles overcome, the first YCH-53A performed its initial flight at the Sikorsky plant in Stratford, Connecticut, on 14 October 1964, about four months behind schedule. The Marines had already placed an initial production contract for 16 helicopters in September. Flight trials went more smoothly than expected, helping make up for the lost time in development. It received the military designation and name "CH-53A Sea Stallion". Delivery of production CH-53s began in 1966.

Further development
The CH-53A arrived in Vietnam in January 1967 and proved useful, eventually recovering even more downed aircraft than the CH-54. A total of 141 CH-53As were built, including the two prototypes. The United States Navy acquired 15 CH-53As from the USMC in 1971 for airborne mine countermeasures (AMCM) activities. The helicopters had more powerful T64-GE-413 turboshafts installed and received the designation "RH-53A".

The United States Air Force ordered the HH-53B in September 1966 and first flew on 15 March 1967. It added a refueling probe, drop fuel tanks and a rescue hoist; it also featured upgraded T64-GE-3 engines. The Air Force used the HH-53B for combat search and rescue (CSAR). HH-53C was an improved CSAR variant with a smaller 450 USgal for improved performance. It also added more armor and better communication systems. The CH-53C was similar except it lacked a refueling probe. It was used by the USAF for more general transport work.



Heavy lifting in tropical climates demanded more power, so the Marines decided to acquire an improved variant, the "CH-53D", with uprated engines, originally the T64-GE-412 then later the T64-GE-413. The CH-53D also included an uprated transmission to go with the more powerful engines, and a revised interior to permit a load of 55 troops.

The initial flight of the CH-53D was on 27 January 1969. The CH-53D served alongside the CH-53A through the rest of the Vietnam War. A VIP transport version designated, "VH-53D" with plush accommodations was used by the Marines for the US presidential flights. The US Navy also acquired CH-53D based helicopters for mine sweeping. These were designated "RH-53D" and included mine sweeping gear such as a pair of 0.50 BMG (12.7 mm) Browning machine guns for detonating mines. The Navy received 30 RH-53Ds beginning in 1973. After the RH-53Ds were in service, the RH-53As were handed back to the Marines and restored to CH-53A configuration.

During the 1980s, Israeli Air Force's CH-53 Yas'ur fleet was upgraded and improved by Israel Aircraft Industries, along with military high-tech firm Elbit Systems. The project – which ended only in 1997 – improved the CH-53 avionics, robustness and extended its life span by at least two decades.

In 1989, some of the CH-53As being retired by the Marines were passed on to the U.S. Air Force for training, with these helicopters redesignated "TH-53As". The TH-53As were stripped of most operational equipment and painted in USAF camouflage colors.

Design
The Sea Stallion has a fuselage design similar to the Sikorsky S-61R/Jolly Green Giant series. It has a passenger door on the right side of the fuselage behind the cockpit and a power-operated rear loading ramp. The fuselage was watertight, though not intended for amphibious use, and only landed on water in emergencies. The Stallion has mechanical flight controls which are backed by three independent hydraulic systems. Armor protects crew and vital systems. The CH-53A carries a crew of four; pilot, copilot, crew chief, and an aerial observer, a load of 38 troops, 24 litters with medical attendants, an internal cargo load of 8000 lb or an external load of 13000 lb on the single-point sling hook. The CH-53A is equipped with a pair of 7.62 mm M60 machine guns that point out to each side of the fuselage.

The CH-53A features a six-bladed main rotor and four-bladed tail rotor developed from those used on the S-64 Skycrane. To save space on board naval vessels, the tail boom and the rotors folded. Initially, the CH-53 was powered by twin General Electric T64-6 turboshaft engines providing 2850 shp each, each engine being located on the upper fuselage. Later engines included the T64-1 with 3080 shp and the T64-16 with 3485 shp. The HH-53B featured T64-3 engines producing 3080 shp.

The CH-53D features uprated engines, initially T64-GE-412 with 3695 shp then the T64-413 with 3925 shp with an uprated transmission. Its interior added seats to allow for 55 troops. CH-53Ds are generally armed with twin .50 BMG (12.7 mm) M2/XM218 machine guns. In later years, CH-53Ds have been fitted with defensive countermeasures including an AN/ALE-39 chaff dispenser and an AN/ALQ-157 infrared countermeasure.

Later production CH-53Ds featured a Blade Inspection Method (BIM) scheme to detect cracks in its metal rotors. BIM involved pressurizing the interior of the rotor blades with nitrogen. If a crack is present pressure is lost and a red indicator on the rotor blade tip was tripped. Later, the BIM system was connected to a cockpit display. BIM reduced the need to swap out rotor blades on a routine basis.

United States


The CH-53/HH-53 has seen considerable use in warzones and served in various conflict during its service; starting with the Vietnam War, often as a Special Operations helicopter. 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 the Fall of Saigon.

U.S. Air Force HH-53 Super Jolly Green Giants were the primary search-and-rescue helicopter in Southeast Asia between 1967 and 1975, inserted the Operation Ivory Coast rescue team into the North Vietnamese prison camp at Son Tay in 1970, and carried the Marines and Air Force Security Forces who attempted to rescue the crew of the SS Mayagüez. 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".

The CH-53 is operated by the United States Marine Corps and Air Force in support of Operation Iraqi Freedom and Operation Enduring Freedom in Iraq and Afghanistan. It is also operated by the Navy in support of Operation Iraqi Freedom and Operation Enduring Freedom throughout the region, deployed out of a squadron in Bahrain.

On 12 October 2004 Heavy Lift Helicopters of Apple Valley, California received the first of two CH-53D Sea Stallions from Davis-Monthan Air Force Base for conversion into firefighting aircraft. This modification yields a "Fire Stallion."

On 17 September 2007, VMM-263 of the Marine Corps was deployed with ten MV-22B Ospreys, a tiltrotor aircraft. V-22 Ospreys will replace the Marine Corps CH-46Es and CH-53Ds, but not their CH-53Es. The in-development CH-53K is planned to supplant the Navy and Marine Corps' CH-53Es.

HMH-463 replaced its CH-53Ds with CH-53Es in September 2011. HMH-363 and HMH-362 will operate D-models until the squadrons are deactivated. Both will be reactivated as MV-22 and CH-53K squadrons respectively. Several CH-53D helicopters will be retained for the 3rd Marine Regiment for training. The last CH-53Ds were performing the D-model's last mission in Afghanistan during late February 2012 and were taken out of service afterward.

Israel
In August 1968, an Israeli Air Force delegation went to the Sikorsky plant in Connecticut to choose the service's next assault helicopter. 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. Lessons that had been learned in the Six Day War led the delegation to choose Sikorsky.

The CH-53 was bigger and stronger than the IAF's other helicopters, and represented a new generation of assault helicopters – a leap forward in terms of rescue operations, transport missions and tactical troop landings. In September 1969, in the course of the War of Attrition, the first two CH-53s arrived at the port of Ashdod, and received their Hebrew name, Yas'ur (Petrel). They were sent into action in short order. On 6 August 1970 the first Yas'ur squadron was established. They are the main cargo helicopters of the IAF, carrying troops and heavy equipment.

In 1969, during the War of Attrition, IAF Yas'ur 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). In the 1973 Yom Kippur War, the Yas'urs moved artillery batteries around the fronts, evacuated wounded soldiers and rescued pilots from behind enemy lines. In one engagement, a Yas'ur was damaged by cannon fire from a MiG-21 but returned safely to base. Since 1973, Yas'urs have also been used by the IDF to land and extract Sayeret commandos on deep raids into Lebanon and Syria.

During the 1980s, Israel Aircraft Industries, along with military high-tech firm Elbit Systems, upgraded and improved the IAF Yas'ur fleet. The project, ended in 1997, improved the CH-53 avionics, robustness and extended its life span by at least two decades.

In 1989, Yas'urs were used to fight a huge blaze on Mount Carmel. They performed dozens of low flyovers into the smoke and flames, dumped 700 tons of water on the fire, and doused it.

During the 2006 Lebanon War the Lebanese Hezbollah shot down an Israeli CH-53 Yas'ur with an anti-tank missile, killing five air crew members.

On 16 August 2012, the Israeli Air Force grounded its fleet following a CH-53 having in-flight issue that led to an emergency landing; initial reports state the problem lay with the rotor blades.

Germany
In 1966 the German military evaluated both the CH-53 and CH-47 Chinook as a replacement for the H-21 and H-34G helicopters with an initial requirement for 133. The purchase of the CH-53 was approved in June 1968 but due to budget constraints only 110 were ordered. Following the delivery in 1969 of two pre-production helicopters from Sikorsky the production aircraft were licence built by VFW-Fokker at Speyer in Germany. The first German-built helicopter flew from Speyer on 11 October 1971 and was delivered to the Erprobungsstelle der Bundeswehr 61 flight test centre at Manching on 1 December 1971.

The German Army Aviation Corps received 110 type CH-53Gs. Except for the first two, all machines were built in Germany. The first flight made by a German CH-53G was made in 1971, followed in March 1973 by the delivery of the first machines to Army Aviation Corps Regiment 35 in Mendig, and shortly afterwards to the newly formed Army Aviation Corps Regiment 15 based at Rheine, and Army Aviation Corps Regiment 25 based at Laupheim.

In order to meet ever more demanding specifications, over time the CH-53G received modifications designed to improve its service life and operational capabilities. These involved three major upgrades: new missile warning and self-protection systems; provision for two external fuel tanks allowing range to be increased to 1800 km when carrying 36 armed soldiers or a 5500-kg payload; and addition of a night vision goggles-compatible cockpit for night low-level flying capabilities. All CH-53Gs were upgraded by Eurocopter Germany by early 2001.

German Army Aviaton Corps units have carried out a whole 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. Due to the lower cargo capacities of the NH-90, service life extensions for at least a portion the CH-53 fleet are envisioned, bringing its useful life out to approximately the year 2030.

On 1 January 2013 all Army Aviaton Corps' CH-53Gs were transferred to the German Air Force and incorporated into Helicopter Wing 64.

Variants

 * YCH-53A : Two prototypes with two 2850 shp T64-GE-3 engines.


 * CH-53A : Initial production for USMC, 139 built.


 * RH-53A : CH-53A re-engined with two 3925 shp T64-GE-413 engines as Airborne mine countermeasures (minesweeper) versions for the United States Navy, 15 conversion.


 * TH-53A : Stripped CH-53As used for training by the United States Air Force.


 * CH-53D : CH-53A with improved transmission, larger cabin for 55 troops and automatic rotor blade folding for the United States Marine Corps, 126 built.


 * RH-53D : United States Navy mine countermeasures version of the CH-53D, fitted with 0.50 in guns and provision for air refueling, 30 built for the USN. The Imperial Iranian Navy received 6 RH-53Ds mine sweepers that were acquired before the Iranian Revolution. These were supplemented by five more US Navy RH-53Ds abandoned after Operation Eagle Claw.


 * VH-53D : Two CH-53Ds for USMC VIP transport


 * VH-53F : Six unbuilt VIP helicopters for the US Navy/Marine Corps.


 * CH-53G : German base version of the CH-53D for German Army Aviation Corps. The internal Sikorsky designation was S-65C-1. A total of 112 were produced including 2 pre-production and 20 assembled by VFW-Fokker and 90 built by Speyer., 89 German CH-53s were in service, with 80 planned to be in service in 2014. All German CH-53s are going to receive T64-100 engines (in 3 batches, 1st batch has already been installed, 2nd batch is currently being installed and 3rd batch is planned with funding made available). All will receive IFR-capability.


 * CH-53GS : Update of 20 CH-53Gs with additional missile counter measure, upgraded communication and navigation system and two external fuel tanks in late 1990s. They later received the first batch of T64-100 engines to operate in hot&high conditions as they prevail in Afghanistan as well as MG3 and M3M machine guns. A CH-53GS/GE update has also been ordered to provide combat search-and-rescue (CSAR) capability to 26 helicopters.


 * CH-53GE : A configuration based on CH-53GS combat search-and-rescue (CSAR) capabilities. The upgrade configuration was formerly known as CH-53GSX. It further updates with modern electronics, two external fuel tanks, counter measures and dust filters for the engines. Upgrade was ordered to support Afghanistan deployment.


 * CH-53GA : Update of further 40 CH-53Gs with new flight deck, new flight control system, autopilot, navigation and communication systems, FLIR, ECM and missile counter measures as well as provisions for additional internal fuel tanks. The CH-53GA helicopter successfully completed its first flight in February 2010. The upgrade is to be completed in 2013.


 * S-65C-3 Yas'ur : Export version for the Israel Air Force. The Yas'ur 2000 version are helicopters upgraded and improved by the Israel Aircraft Industries to extend life span past 2000. The Yas'ur 2025 is a further upgraded version with new systems and new gearboxes. Israel has 18 CH-53 2000, 5 Yas'ur 2025 in service.


 * S-65Öe : Export version for the Austrian Air Force. Internal Sikorsky designation was S-65C-2.


 * For other variants, see HH-53 "Super Jolly Green Giant"/MH-53 Pave Low and CH-53E Super Stallion.

Operators

 * 🇩🇪 Germany
 * German Air Force – 60
 * German Army Aviation Corps
 * 🇮🇷 Iran
 * Islamic Republic of Iran Navy – 3
 * 🇮🇱 Israel
 * Israeli Air Force – 23
 * 🇲🇽 Mexico
 * Mexican Air Force – 4

Former operators
.
 * 🇦🇹 Austria
 * Austrian Air Force -2
 * 🇺🇸 United States
 * United States Air Force (see MH-53 Pave Low)
 * United States Marine Corps
 * United States Navy

Accidents and incidents
Due to its large size and troop capacity, aerial accidents that involve CH-53 helicopters were some of the deadliest helicopter accidents ever.


 * On 10 May 1977, a CH-53 crashed in Israel, resulting in the deaths of 54 people.
 * On 21 October 1977, a CH-53 crashed in Mindoro, Philippines during sling load operations due to a design flaw in the tail rotor drive; 31 US Marines serving in Operation Fortress Lightning were killed.
 * On 11 December 1978, a CH-53G of the German Army Aviation Corps' Medium Transport Helicopter Regiment 25 crashed at Laupheim Air Base, Germany. During landing and poor visibility the tail rotor hit the ground. Of the four occupants, one was killed.
 * On 26 November 1980, a CH-53G of the German Army Aviation Corps' Medium Transport Helicopter Regiment 15 crashed in a forest near Wippenkausen, North Rhine-Westphalia, Germany. All four occupants were killed.
 * On 27 April 1983, a CH-53D crashed in the Atlantic off the coast of Virginia. The crash resulted in the drowning of Marine 1st Lt David A. Boyle. The suit brought by Boyle's father went to the Supreme Court.
 * On 24 March 1984, a CH-53D crashed into a mountain in Korea during a night troop operation, killing 29.
 * On 6 May 1985, a CH-53D experienced a transmission failure and fell into Sea of Japan while returning to Futenma AB from Iwakuni AB, Yamaguchi Prefecture, killing 17. It belonged to the 462nd Helicopter Squadron, 36th Wing, 1st Group, USMC, based at Futenma AB.
 * On 20 March 1989, a Sea Stallion crashed while on maneuvers off mountainous east coast of South Korea, near P'ohang. 22 onbaord were killed. Sixteen other Marines, including one on the ground, were injured in the crash.
 * On 18 May 1990, a Marine Corps CH-53D Sea Stallion en route to its base at the Marine Corps Air Station Tustin crashed in Imperial County, killing one crew member and injuring five others. At the time more than 200 servicemen had been killed in accidents involving the CH-53A, CH-53D, and CH-53E from 1969 to 1990.
 * On 14 March 1994, a CH-53D landed tail-first and burst into flames on a military runway in Northern California. One Marine was killed and four Marines were injured.
 * On 4 February 1997, two CH-53s collided in the "Helicopter Disaster" in Israel. A total of 73 people died in the accident.
 * On 21 December 2002, a CH-53G of the German Army Aviation Corps' Medium Transport Helicopter Regiment 25 crashed near Kabul killing all seven occupants. An investigation following the accident concluded that the crash was caused by mechanical failure.
 * On 13 August 2004, a US Marine CH-53D from Marine Corps Air Station Futenma crashed into Okinawa International University on Okinawa, Japan. No serious damage or injuries resulted but it was a major international incident because of strained relations about the US use of Futenma. The crash was caused by a maintenance error.
 * On 28 November 2008, a CH-53G of the German Army Aviation Corps' Medium Helicopter Transport Regiment 25 crashed during an exercise at an altitude of 8,500 feet (2,600 m) near Engelberg in the Swiss Alps, injuring one of the six occupants. The recovery of the helicopter was not completed until June 2009.
 * On 26 July 2010, an Israeli CH-53 crashed during a training flight in the Carpathian mountains in Romania killing 6 Israeli soldiers and one Romanian.
 * On 29 March 2011, a Marine CH-53D from MCBH Kaneohe Bay crashed into the bay, killing 1 and injuring 3.
 * On 19 January 2012, a Marine CH-53 crashed in southern Afghanistan. Six International Security Assistance Force (ISAF) troops, all U.S. Marines were killed in the accident.