Sikorsky CH-53 Sea Stallion

Origins In 1960, the United States Marine Corps (USMC) began to seek a replacement for their HR2S piston-powered helicopters. 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. 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-53C was an improved CSAR variant with a smaller fuel tank in exchange for 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. CH-53Ds landing 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. 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 USMC for the US presidential flights. The US Navy also acquired CH-53D-based helicopters for minesweeping. 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 USMC and restored to CH-53A configuration. During the 1980s, Israeli Air Force's CH-53 ''Yas'ur'' fleet was upgraded by Israel Aircraft Industries and 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 USMC 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 Sikorsky CH-53 Sea Stallion is a heavy lift military transport helicopter. The CH-53A carries a crew of four; pilot, copilot, crew chief, and an aerial observer. It can carry various payloads, including up to 38 fully-equipped troops, 24 litters with medical attendants, an internal cargo load of , or an external load of on the single-point sling hook. Initially, the CH-53 was powered by a pair of General Electric T64-6 turboshaft engines, each of which provided up to . These engines were located on the upper fuselage. Later engines included the T64-1, capable of generating up to , and the T64-16, which was rated for up to . The HH-53B model featured T64-3 engines, which produced up to . The improved CH-53D features uprated engines, initially using the T64-GE-412 that could provide up to , then the T64-413 with its further elevated output of ; these more powerful engines necessitated the use of an uprated transmission. Interior changes included additional seats, which allowed for up to 55 troops to be carried at a time. The CH-53D is generally armed with twin .50 BMG (12.7 mm) M2/XM218 machine guns. During the type's later years of service, it has become commonplace for CH-53Ds to have been retrofitted with various defensive countermeasures; such apparatus has often included 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 routinely swap rotor blades. ==Operational history==

United States The CH-53/HH-53 has seen considerable use in warzones and served in various conflict during its service. It was first used in the Vietnam War, often recovering downed aircraft and evacuating personnel. 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. 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 USMC and Air Force Security Forces who attempted to rescue the crew of 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". Marine CH-53s were used in Grenada during Operation Urgent Fury. The CH-53 was operated by the Air Force, Marine Corps and Navy in support of Operation Iraqi Freedom. It is also operated by all three services in support of Operation Enduring Freedom in Afghanistan. It was in the Afghan theatre than the final operational missions of the CH-53D fleet were performed during February 2012. On 17 September 2007, VMM-263 of the USMC was deployed with ten MV-22B Ospreys, a tiltrotor aircraft. The V-22 has been the primary replacement for the USMC's fleets of CH-53Ds and CH-46E Sea Knights, but not the more powerful CH-53Es; instead, the in-development CH-53K is planned to supplant the Navy and USMC CH-53E fleets. During September 2011, HMH-463 replaced its CH-53Ds with CH-53Es. HMH-363 and HMH-362 are to operate D-models until the squadrons are deactivated. Both units are to be reactivated as MV-22 and CH-53K squadrons respectively. Several CH-53D helicopters will be retained for the 3rd Marine Regiment for training. HMH-362 retired the last CH-53Ds after its combat deployment in August 2012 and decommissioned in November 2012. Israel 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. soldier with a stretcher On 2 October 1969, the first S-65C-3 (CH-53D) helicopters were delivered to Israel of an initial order of seven. 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. This was reportedly the only combat loss of an Israeli CH-53 during this conflict. 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. 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. During 2015, it was announced that Israel planned to withdraw the last of its Yasurs around 2025. Replacement options studied included the CH-53K and the CH-47F Chinook, with a prospective order for approximately 20 helicopters being placed for the preferred option. During February 2021, the Israeli Ministry of Defense announced the selection of the CH-53K to replace the Yasur fleet. On 7 October 2023, during the first day of the Gaza war, and the first time since the 2006 Lebanon War in a similar incident, Hamas shot down an IAF CH-53 with Kornet anti-tank missile and hitting its left engine, while carrying about 50 paratroopers (a very unusual procedure, as opposed to the approved IAF's max capacity of 33 troops). The pilot managed to land safely in an open field, offloading both the aircrew and the paratroopers. The CH-53 was then hit by a second anti-tank missile, completely destroying the helicopter. The occupants survived the attack with minor to medium injuries. Iran During the 1970s, an initial fleet of six RH-53D Sea Stallions was delivered to the Imperial Iranian Navy (IIN). Following the Iranian Revolution in 1979, the Sea Stallions continued in service with the renamed Islamic Republic of Iran Navy (IRIN). Despite US sanctions that have blocked the nation from acquiring spares and support from overseas, Iran has reportedly been able to keep at least a portion of their Sea Stallions in an operational condition; this effort has been aided by illegal exports of controlled parts to Iran by US citizens. Germany In 1966, the German military evaluated both the CH-53 and CH-47 as a replacement for the H-21 and H-34G helicopters with an initial requirement for 133. During the 2010s, Germany was reportedly considering options for replacing its aging CH-53G fleet, with candidates including the Chinook and the CH-53K model. On 29 September 2020, the German Ministry of Defense cancelled the "Schwerer Transporthubschrauber" (STH) heavy-lifting helicopter program for 45 to 60 helicopters after the initiative was judged to be too expensive and stated that its CH-53Gs fleet would be replaced following a period of reexamination. In 2022, the Federal Government announced that all of Germany's CH-53s would be replaced by 60 CH-47Fs. Austria parked at RAF Greenham Common in 1974 During 1970, a pair of S-65C-2 or S-65Ö (equivalent to the CH-53D standard, albeit without the aerial refuelling probe) helicopters were delivered to Austria. Intended primarily to perform airborne rescue operations in the Alps, they were assigned to 1st Helicopter Wing of the Austrian Air Force, making the service the second foreign operator of the CH-53. However, since the 1999 Galtür avalanche, in which over 7000 thousand people had transported by international collaboration of helicopter resources from Austria, USA, German, France, and Switzerland including 50 helicopters, more helicopter resources have been pursued. Mexico During 2003, the Fuerza Aérea Mexicana (FAM) acquired four surplus CH-53D Sea Stallions from Israel at a combined cost of $25 million (~$ in ). Prior to their delivery in 2005, all helicopters were upgraded to the Yasur 2000 standard. Due to restricted budgets, only two were actually operated by 104th Air Squadron, while the other pair served as a source of spare parts. Their initial missions were troop transport and commando insertion, but their principal mission was subsequently changed to performing rescue and disaster relief operations, being relocated to BAM 8 at Yucatán. By 2013, all examples had been permanently withdrawn from service. Civil use During 2007, the first commercially owned CH-53D was being converted by the Californian company Heavy Lift Helicopters into a firefighting configuration, which was referred to by the firm as the Fire Stallion Having acquired a batch of six ex-military CH-53Ds, the company planned to make them available for hire by other operators; in addition to fire-fighting, construction work and general transport duties were envisioned for the fleet. While the fleet reportedly flew for a handful of years, they entered storage after only a short period of use due to component shortages. ==Variants==

;YCH-53A: Two prototypes with two T64-GE-3 engines. ;CH-53A: Initial production variant for the USMC. 139 built. ;RH-53A: CH-53A re-engined with two T64-GE-413 engines as Airborne Mine CounterMeasures (AMCM) variants for the United States Navy. 15 conversions. ;TH-53A: Stripped CH-53As used for training by the United States Air Force. ;CH-53D: CH-53A with an 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 AMCM variant of the CH-53D, fitted with 0.50-inch caliber machine guns and provision for air refueling. 30 built for the USN. Six examples were also exported to Iran, before the Iranian Revolution in 1979. ;VH-53D: Four modified 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 the 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; first batch has already been installed, second 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 in the late 1990s, with additional missile counter measure, upgraded communication and navigation system and two external fuel tanks added. 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 was completed by 2013. ;S-65Ö: Export version of the CH-53D for the Austrian Air Force. Internal Sikorsky designation was S-65C-2. Only 2 were built, subsequently sold to Israel. Israel completed the upgrade by 2015 and currently operates 21 Yas'urs as of November 2023. == Operators ==

during Israel's 65th Independence Day flypast in 2013 ; • German Air Force • Helicopter Wing 64 ; • Islamic Republic Iranian Navy 1970–1981 (sold to Israel) ; • German Army Aviation Corps • Medium Transport Helicopter Regiment 15 Münsterland, 1971–2012 (disbanded) • Medium Transport Helicopter Regiment 25 Oberschwaben, 1971–2012 (initially disbanded, later reformed in 2013 as Helicopter Wing 64 in the German Air Force) ; • Mexican Air Force (All remaining USN RH-53D Sea Stallions were transferred to the USMC in 1993 and all AMCM USN HM units had converted to the MH-53E Sea Dragon by 1995) • HM-12 "Sea Dragons", 1971-1994 (reestablished 2015-present with MH-53E Sea Dragon) • HM-14 "Vanguard", 1978-1989 (converted to MH-53E Sea Dragon 1989-2023) • HM-15 "Blackhawks", 1993-1994 (established in 1987 as an MH-53E squadron; supported HM-19 as Det. 3 or "Pink Det." integration from RH-53D to MH-53E Sea Dragon) • HM-16 "Seahawks", 1978-1987 (was exclusively an RH-53D squadron) • HM-18 "Norsemen", 1986-1995 (RH-53D squadron that integrated with HM-14 with MH-53E Sea Dragon) • HM-19 "Golden Bears", 1988-1993 (RH-53D squadron that integrated with HM-15 with MH-53E Sea Dragon) ==Aircraft on display==

Israel ;On display • 471 (#65-078) - CH-53A on display at Israeli Air Force Museum, Hatzerim Airbase, Israel. United States ;On display • 151686 - CH-53A on display at Paxtuxent River Naval Air Museum, Lexington Park, Maryland. • 153304 – CH-53A on display at Flying Leatherneck Aviation Museum, MCAS Miramar, California. • 153715 - CH-53A on display at Fort Worth Aviation Museum, Fort Worth, Texas • 157159 - CH-53D on display at National Naval Aviation Museum, NAS Pensacola, Florida. • 158690 - RH-53D on display at Air Victory Museum, Lumberton, New Jersey. ==Accidents and incidents==

Due to the aircraft's large size and troop capacity, aerial accidents involving CH-53 helicopters have been some of the deadliest helicopter accidents. on 19 July 1981. While operating 50 km southeast of Morehead City, North Carolina (USA), a Sikorsky CH-53 Sea Stallion crashed into another CH-53 and a Bell UH-1N Twin Huey upon landing • On 23 June 1967, USMC CH-53A Bu. no #65-082 collided with a US Army UH-1B #63-8572 while taking off from Camp Lejeune, all 20 marines on board were killed along with two occupants of the UH-1B. • On 8 January 1968, USMC CH-53A #65-100 of HMH-463 crashed in the Hải Lăng Forest south of Đông Hà Combat Base, killing all 46 personnel on board. • On 19 February 1968, USMC CH-53A #65-055 crashed into Monkey Mountain killing all 13 personnel on board. • On 22 February 1968, USMC CH-53A #65-060, was hit by antiaircraft fire and crashed at Khe Sanh Combat Base, killing two marines. • On 1 May 1968, USMC CH-53A #65-058 crashed into the sea off Quảng Trị Province killing one crewman. • On 28 July 1968, USMC CH-53A #65-061 crashed south of Danang killing all five crewmen. • On 1 September 1969, USMC CH-53A #65-059 crashed in Thừa Thiên Province killing all five crewmen. • On 13 September 1970, USMC CH-53D #65-181 was hit by antiaircraft fire and crashed with no fatalities. • On 26 October 1970, USMC CH-53D #65-192 crashed on a test flight near Danang, killing one crewman. • On 30 October 1970, USMC CH-53D #65-259 was hit by antiaircraft fire and crashed in Quảng Nam Province, killing two crewmen. • On 18 February 1971, USAF CH-53C #65-227 of 21st Special Operations Squadron was hit by antiaircraft fire and crashed in Laos with no fatalities. • On 8 February 1971, USMC CH-53D #65-189 crashed near Huế, killing all nine personnel on board. • On 1 March 1971, USAF CH-53C #65-229 of 21st Special Operations Squadron was hit by antiaircraft fire and crashed near Long Tieng, killing six personnel. • On 11 July 1972, USMC CH-53D #65-177 was hit by a surface to air missile and crashed near Quảng Trị, killing three crewmen and 45 South Vietnamese marines. • On 24 January 1975, USAF CH-53C #65-338 of 21st Special Operations Squadron suffered main rotor head failure and crashed near Nakhon Phanom Royal Thai Navy Base, killing all four personnel on board. • On 13 May 1975, USAF CH-53C #65-231 of 21st Special Operations Squadron crashed west of Nakhon Phanom Royal Thai Air Force Base, killing 23 Air Force personnel • On 15 May 1975, during the Mayaguez Incident, three CH-53s of the 21st Special Operations Squadron were shot down by the Khmer Rouge, resulting in the deaths of ten marines, two Navy Corpsmen and two Air Force crewmen. • On 26 September 1975, USAF CH-53C #65-342 of the 601st Tactical Air Support Squadron crashed near Delbrück (Paderborn) Germany killing 16 personnel on board. • 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 in poor visibility the tail rotor hit the ground. Of the four occupants, one was killed. • On 25 April 1980, six USN RH-53s were lost in Operation Eagle Claw, the failed attempt to rescue American hostages in Iran. • 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 14 September 1982, CH-53A #65-083 crashed into the North Sea off the coast of Denmark during NATO exercise "Northern Wedding" killing all 5 servicemen aboard. the Pilot, Capt. William H. "Sonny" Coke; Co-Pilot Capt James B. Huff; Crew Chief SSgt. Gary J. "Butch" Lester; Sgt. Timothy A. "Tim" Creighton; and chaplain, Navy Cdr. David R. Morrison. The Sea Stallion was part of Marine Heavy Helicopter Squadron-777. • 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 South 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, killing 17. • On 18 May 1990, a USMC CH-53D en route to Marine Corps Air Station Tustin crashed in Imperial County, California, killing one crew member and injuring five others. In climbing flight, a pitch lock engaged in one main rotor blade causing a violent vibration that resulted in the tail rotor departing the aircraft at AGL. Torque and rapid rotation contributed to the aircraft breaking apart further just aft of the main transmission. Auto-rotation resulted a bounce, roll over and fire. Auxiliary tanks were attached. 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 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 23 November 2003, a MH-53M crashed near Bagram Air Base in Afghanistan. Five U.S. servicemen were killed. • On 13 August 2004, a USMC CH-53D from Marine Corps Air Station Futenma into Okinawa International University on Okinawa, Japan. No serious damage or injuries resulted but the crash caused an international incident because of strained relations about the US use of Futenma. The crash was caused by a maintenance error. • On 28 November 2008, CH-53G Registration 84+36 of the German Army Aviation Corps' Medium Helicopter Transport Regiment 25 had a hard landing during an exercise at an altitude of 6,900 feet (2,300 m) near Engelberg in the Swiss Alps, injuring one of the six occupants. The dismantling and partial recovery of the helicopter wreckage was completed in June 2009 by helilifting 84+36 slung below her sister 84+32 down to the village of Alpnach. • On 26 July 2010, an Israeli CH-53 crashed during a training flight in the Carpathian mountains in Romania, killing six Israeli soldiers and one Romanian. • On 29 March 2011, a USMC CH-53D from MCBH Kaneohe Bay crashed into the bay, killing one and injuring three. • On 19 January 2012, a USMC CH-53D crashed in southern Afghanistan. Six International Security Assistance Force (ISAF) troops, all marines, were killed in the accident. ==Specifications (CH-53D)==

door gunner on board a CH-53 ==See also==