Misplaced Pages

#171828

131-798: The CH-53 Sea Stallion ( Sikorsky S-65 ) is an American family of heavy-lift transport helicopters designed and built by the American manufacturer Sikorsky Aircraft . The Sea Stallion was originally developed in response to a request from the United States Navy 's Bureau of Naval Weapons made in March 1962 for a replacement for the Sikorsky CH-37 Mojave helicopters flown by the United States Marine Corps (USMC). In July 1962, Sikorsky's proposal, which

262-519: 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. The CH-53/HH-53 has seen considerable use in warzones and served in various conflict during its service. It

393-616: A runway . In 1942, the Sikorsky R-4 became the first helicopter to reach full-scale production . Although most earlier designs used more than one main rotor, the configuration of a single main rotor accompanied by a vertical anti-torque tail rotor (i.e. unicopter , not to be confused with the single-blade monocopter ) has become the most common helicopter configuration. However, twin-rotor helicopters (bicopters), in either tandem or transverse rotors configurations, are sometimes in use due to their greater payload capacity than

524-636: 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

655-537: A 100-nautical-mile (190 km) radius was maintained. Vought responded with a proposal combining engineering from their own design arm, as well as Ryan and Hiller , who had more extensive helicopter experience. Their proposal won the design contest, and a contract for five prototypes was signed in early 1962 with first flight specified for July 1964. The design was initially known as the Vought-Ryan-Hiller XC-142, but when Vought became part of

786-628: A 12,100 lb (5,500 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, resulting in updated GS/GE/GA variants. As a result of foreign military operations 20 CH-53G helicopters were converted to perform Combat Search and Rescue (CSAR) missions. Version CH-53GS is equipped with modernized IFR equipment, additional exterior fuel tanks, low-flight night vision cockpit and NVG, partial ballistic protection, engine dust collectors, missile counter measure and self-defence armament. Additionally

917-444: A collective input is made, all the blades change equally, and the result is the helicopter increasing or decreasing in altitude. A swashplate controls the collective and cyclic pitch of the main blades. The swashplate moves up and down, along the main shaft, to change the pitch of both blades. This causes the helicopter to push air downward or upward, depending on the angle of attack . The swashplate can also change its angle to move

1048-417: A constant altitude. The pedals serve the same function in both a helicopter and a fixed-wing aircraft, to maintain balanced flight. This is done by applying a pedal input in whichever direction is necessary to center the ball in the turn and bank indicator . Due to the operating characteristics of the helicopter—its ability to take off and land vertically, and to hover for extended periods of time, as well as

1179-556: A few more flights and achieved a height of nearly 2.0 metres (6.5 ft), but it proved to be unstable and was abandoned. LTV XC-142 In 1959 the United States Army , Navy and Air Force began work on the development of a prototype V/STOL aircraft that could augment helicopters in transport-type missions. Specifically they were interested in designs with longer range and higher speeds than existing helicopters, in order to support operations over longer distances, or in

1310-463: A gift by their father, would inspire the Wright brothers to pursue the dream of flight. In 1861, the word "helicopter" was coined by Gustave de Ponton d'Amécourt , a French inventor who demonstrated a small steam-powered model. While celebrated as an innovative use of a new metal, aluminum, the model never lifted off the ground. D'Amecourt's linguistic contribution would survive to eventually describe

1441-405: A helicopter determines the size, function and capability of that helicopter design. The earliest helicopter engines were simple mechanical devices, such as rubber bands or spindles, which relegated the size of helicopters to toys and small models. For a half century before the first airplane flight, steam engines were used to forward the development of the understanding of helicopter aerodynamics, but

SECTION 10

#1732780864172

1572-510: A helicopter powered by a gasoline engine with box kites attached to a mast by cables for a rotor, but it never flew. In 1906, two French brothers, Jacques and Louis Breguet , began experimenting with airfoils for helicopters. In 1907, those experiments resulted in the Gyroplane No.1 , possibly as the earliest known example of a quadcopter. Although there is some uncertainty about the date, sometime between 14 August and 29 September 1907,

1703-416: A helicopter. This is because a helicopter generates its own gusty air while in a hover, which acts against the fuselage and flight control surfaces. The result is constant control inputs and corrections by the pilot to keep the helicopter where it is required to be. Despite the complexity of the task, the control inputs in a hover are simple. The cyclic is used to eliminate drift in the horizontal plane, that

1834-642: A high pilot workload. Additionally, it proved susceptible to problems due to wing flexing. Shaft problems, along with operator errors, resulted in a number of hard landings causing damage. One crash occurred as a result of a failure of the driveshaft to the tail rotor, causing three fatalities. One of the limitations found in the aircraft was an instability between wing angles of 35 and 80 degrees, encountered at extremely low altitudes. There were also high side forces which resulted from yaw and weak propeller blade pitch angle controls. The new "2FF" propellers also proved to generate less thrust than predicted. The basic design

1965-416: A loadmaster. The wing was high-mounted and the tail surfaces were cruciform to keep the rear area clear during loading. Tricycle landing gear were used, with the main legs retracting into blisters on the fuselage sides. In normal parked configuration it would appear to be a conventional cargo plane. For V/STOL operations, the aircraft "converted" by tilting its wing to the vertical. Roll control during hover

2096-462: A lower empty weight than preceding designs as well. 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

2227-545: A pair of 7.62×51mm NATO M60 machine guns that point out to each side of the fuselage. The CH-53A features a fully-articulated six-bladed main rotor and four-bladed tail rotor. According to Carter, the relatively high speed requirement stipulated by the USMC was the primary factor shaping the dynamic design. 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

2358-415: A premium on board most naval vessels, both the tail boom and the rotors can be folded while the helicopter is stowed; to reduce the workload involved in this process, an automated folding system was developed by Sikorsky. Both the crew and vital systems are protected by armouring across key areas. All of the fuel was housed within sponsons on either side of the fuselage. The CH-53A was typically equipped with

2489-477: A process of rebracketing , the word is often (erroneously, from an etymological point of view) perceived by English speakers as consisting of heli- and -copter , leading to words like helipad and quadcopter . English language nicknames for "helicopter" include "chopper", "copter", "heli", and "whirlybird". In the United States military, the common slang is "helo" pronounced /ˈhiː.loʊ/. A helicopter

2620-602: 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 US gallons (1,700 L) 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. Heavy lifting in tropical climates demanded more power, so

2751-507: A revised specification that specified the same payload, but extended the operational radius to 250 miles (400 km) and increased the cruising airspeed to 250–300 knots (460–560 km/h) and the maximum airspeed to 300–400 knots (560–740 km/h). However, for the Marine Corps mission, the requirement stated that the fuel load could be reduced so that the maximum gross weight would not exceed 35,000 pounds (16,000 kg), as long as

SECTION 20

#1732780864172

2882-494: A rotor. The spinning creates lift, and the toy flies when released. The 4th-century AD Daoist book Baopuzi by Ge Hong ( 抱朴子 "Master who Embraces Simplicity") reportedly describes some of the ideas inherent to rotary wing aircraft. Designs similar to the Chinese helicopter toy appeared in some Renaissance paintings and other works. In the 18th and early 19th centuries Western scientists developed flying machines based on

3013-457: A shortage of engineering resources plus various failures of subcontractors and the government, but these problems were gradually overcome. There was also pressure against the program from U.S. Secretary of Defense Robert S. McNamara , who promoted the concept of "commonality" between the armed services by adopting the Chinook instead. However, the USMC managed to convince McNamara's staff that

3144-441: A single main rotor, but torque created by its aerodynamic drag must be countered by an opposed torque. The design that Igor Sikorsky settled on for his VS-300 was a smaller tail rotor. The tail rotor pushes or pulls against the tail to counter the torque effect, and this has become the most common configuration for helicopter design, usually at the end of a tail boom . Some helicopters use other anti-torque controls instead of

3275-417: A state called translational lift which provides extra lift without increasing power. This state, most typically, occurs when the airspeed reaches approximately 16–24 knots (30–44 km/h; 18–28 mph), and may be necessary for a helicopter to obtain flight. In forward flight a helicopter's flight controls behave more like those of a fixed-wing aircraft. Applying forward pressure on the cyclic will cause

3406-455: A tailwind. The XC-142 was powered by four General Electric T64 turboshaft engines cross-linked on a common driveshaft, which eliminated engine-out asymmetric thrust problems during V/STOL operations, to drive four 15.5-foot (4.7 m) Hamilton Standard fiberglass propellers. Compared to conventional designs it was overpowered: it had 0.27 hp/lb, compared to 0.12 hp/lb for the contemporary Lockheed C-130D Hercules . This extra power

3537-429: Is a cylindrical metal shaft that extends upwards from the transmission. At the top of the mast is the attachment point for the rotor blades called the hub. Main rotor systems are classified according to how the rotor blades are attached and move relative to the hub. There are three basic types: hingeless, fully articulated, and teetering; although some modern rotor systems use a combination of these. Most helicopters have

3668-412: 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 8,000 pounds (3,600 kg), or an external load of 13,000 pounds (5,900 kg) on the single-point sling hook. Access to the main cabin

3799-460: Is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors . This allows the helicopter to take off and land vertically , to hover , and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing ( STOL ) or short take-off and vertical landing ( STOVL ) aircraft cannot perform without

3930-452: Is a type of rotorcraft in which lift and thrust are supplied by one or more horizontally-spinning rotors. By contrast the autogyro (or gyroplane) and gyrodyne have a free-spinning rotor for all or part of the flight envelope, relying on a separate thrust system to propel the craft forwards, so that the airflow sets the rotor spinning to provide lift. The compound helicopter also has a separate thrust system, but continues to supply power to

4061-452: Is called an aerial crane . Aerial cranes are used to place heavy equipment, like radio transmission towers and large air conditioning units, on the tops of tall buildings, or when an item must be raised up in a remote area, such as a radio tower raised on the top of a hill or mountain. Helicopters are used as aerial cranes in the logging industry to lift trees out of terrain where vehicles cannot travel and where environmental concerns prohibit

Sikorsky CH-53 Sea Stallion - Misplaced Pages Continue

4192-547: Is equipped to stabilize and provide limited medical treatment to a patient while in flight. The use of helicopters as air ambulances is often referred to as " MEDEVAC ", and patients are referred to as being "airlifted", or "medevaced". This use was pioneered in the Korean War , when time to reach a medical facility was reduced to three hours from the eight hours needed in World War II , and further reduced to two hours by

4323-660: Is one of the largest military helicopters in service. Germany is planning to replace its fleet, as of the 2020s, with the latest version of the twin-rotor CH-47 Chinook . The latest version of the CH-53, the K model King Stallion is in production as of the 2020s entering service with the United States Marine Corps; this is replacing the Super Stallion, itself an upgraded version of Sea Stallion. The heavily upgraded Jolly Green Giant and Pave Low versions of

4454-678: Is the Sud-Ouest Djinn , and an example of the hot tip jet helicopter is the YH-32 Hornet . Some radio-controlled helicopters and smaller, helicopter-type unmanned aerial vehicles , use electric motors or motorcycle engines. Radio-controlled helicopters may also have piston engines that use fuels other than gasoline, such as nitromethane . Some turbine engines commonly used in helicopters can also use biodiesel instead of jet fuel. There are also human-powered helicopters . A helicopter has four flight control inputs. These are

4585-411: Is to control forward and back, right and left. The collective is used to maintain altitude. The pedals are used to control nose direction or heading . It is the interaction of these controls that makes hovering so difficult, since an adjustment in any one control requires an adjustment of the other two, creating a cycle of constant correction. As a helicopter moves from hover to forward flight it enters

4716-545: 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. This loading ramp was capable of facilitating drive-on loading operations, enabling quicker cargo movements. The CH-53A was designed to have a useful payload capacity, in terms of weight, of almost half of the rotorcraft's empty weight. It is provisioned with mechanical flight controls, which are backed by three independent hydraulic systems. As noted by Sikorsky engineer Edward S Carter Junior,

4847-563: 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. During 2003, the Fuerza Aérea Mexicana (FAM) acquired four surplus CH-53D Sea Stallions from Israel at a combined cost of $ 25 million (~$ 39.7 million in 2023). Prior to their delivery in 2005, all helicopters were upgraded to

4978-673: 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. 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. 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

5109-713: 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. Their equipment included same rescue hoist as the HH-53 and fittings for auxiliary fuel tanks and accommodation for 38 passengers. Although they performed well in high altitude operations, the type's relatively high operating costs were a major contributing factor in Austria's decision to sell both rotorcraft to Israel in 1981. However, since

5240-572: The Bell 205 and the Erickson S-64 Aircrane helitanker. Helicopters are used as air ambulances for emergency medical assistance in situations when an ambulance cannot easily or quickly reach the scene, or cannot transport the patient to a medical facility in time. Helicopters are also used when patients need to be transported between medical facilities and air transportation is the most practical method. An air ambulance helicopter

5371-588: The Bell 206 with 3,400. Most were in North America with 34.3% then in Europe with 28.0% followed by Asia-Pacific with 18.6%, Latin America with 11.6%, Africa with 5.3% and Middle East with 1.7%. The earliest references for vertical flight came from China. Since around 400 BC, Chinese children have played with bamboo flying toys (or Chinese top). This bamboo-copter is spun by rolling a stick attached to

Sikorsky CH-53 Sea Stallion - Misplaced Pages Continue

5502-570: The CH-54 . A total of 141 CH-53As were built, including the two prototypes. The U.S. 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 it first flew on 15 March 1967. It added

5633-527: The Cornu helicopter which used two 6.1-metre (20 ft) counter-rotating rotors driven by a 24 hp (18 kW) Antoinette engine. On 13 November 1907, it lifted its inventor to 0.3 metres (1 ft) and remained aloft for 20 seconds. Even though this flight did not surpass the flight of the Gyroplane No. 1, it was reported to be the first truly free flight with a pilot. Cornu's helicopter completed

5764-582: The German Air Force and incorporated into Helicopter Wing 64 . 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

5895-679: The Iranian Revolution in 1979, the Sea Stallions continued in service with the renamed Islamic Republic of Iran Navy (IRIN). These were supplemented by five U.S. Navy examples that were abandoned during Operation Eagle Claw in 1980. 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. In 1966,

6026-633: 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 Israel-Hamas war , and the first time since the 2006 Lebanon War in a similar incident, Hamas shot down an IAF CH-53 with an anti-tank rocket and hitting its left engine, while carrying about 50 paratroopers (a very unusual procedure, as opposed to

6157-577: The LTV XC-142 tiltwing . The design became more elaborate and the program stretched out, causing the USMC to drop out when they decided they would not receive a working machine in a satisfactory timeframe. In particular, there were concerns that the high levels of downwash produced by the XC-142A would render shipborne operations impractical. In the end, the XC-142A, although a very innovative and capable machine, never entered production. In March 1962,

6288-486: The Ling-Temco-Vought (LTV) conglomerate this naming was dropped. During the prototype development the Navy decided to exit the program. They were concerned that the strong propeller downwash would make it difficult to operate. Their existing HR2S fleet had a ground pressure of about 7.5 psi (500 hPa), and proved to blow people about on the ground and stir up considerable amounts of debris. The C-142

6419-735: 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

6550-481: 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)". 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

6681-499: The Vietnam War . In naval service a prime function of rescue helicopters is to promptly retrieve downed aircrew involved in crashes occurring upon launch or recovery aboard aircraft carriers. In past years this function was performed by destroyers escorting the carrier, but since then helicopters have proved vastly more effective. Police departments and other law enforcement agencies use helicopters to pursue suspects and patrol

SECTION 50

#1732780864172

6812-517: The Vietnamese theater ; the CH-53 quickly proved its value for moving heavy payloads, particularly in the recovery of damaged aircraft. Several variants of the type were promptly introduced. 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;

6943-516: The 1973 Yom Kippur War , the Yas'ur routinely moved artillery batteries and for the insertion of IDF units around the fronts. The type was also used to evacuate hundreds of wounded soldiers and rescued pilots from behind enemy lines in both Egypt and Syria. In one engagement, a single Yas'ur was attacked by multiple aircraft, including a pair of MiG-21s ; while sustaining damage, it was still able to return to base. Since 1973, Yas'urs have also been used by

7074-593: 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. The Sikorsky CH-53 Sea Stallion

7205-555: The Air Force test team in July 1965. During the XC-142A program, a total of 420 hours were flown in 488 flights. The five XC-142As were flown by 39 different military and civilian pilots. Tests included carrier operations, simulated rescues, paratroop drops, and low-level cargo extraction. During testing the aircraft's cross-linked driveshaft proved to be its Achilles heel . The shaft resulted in excessive vibration and noise, resulting in

7336-558: The Bambi bucket, are usually filled by submerging the bucket into lakes, rivers, reservoirs, or portable tanks. Tanks fitted onto helicopters are filled from a hose while the helicopter is on the ground or water is siphoned from lakes or reservoirs through a hanging snorkel as the helicopter hovers over the water source. Helitack helicopters are also used to deliver firefighters, who rappel down to inaccessible areas, and to resupply firefighters. Common firefighting helicopters include variants of

7467-813: 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 turboshaft engines and the dynamic system of the S-64 / CH-54 , 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

7598-504: The C-142B proposal, the tri-services management team could not develop a requirement for a V/STOL transport. XC-142A testing ended, and the remaining flying copy was turned over to NASA for research testing from May 1966 to May 1970. In service it would carry 32 equipped troops or 8,000 pounds (4,000 kg) of cargo. It had maximum gross weight of 41,000 pounds (19,000 kg) for a vertical take-off and 45,000 pounds (20,000 kg) for

7729-482: The CH-53 were made, leading to several international operators of the type. Among these are Germany, Iran, and Israel. Several unusual or high-profile operations have been undertaken, such as the capture and transportation of a Soviet advanced radar system to Israel under Operation Rooster 53 in 1969, and Iran's capture of five American CH-53s as a result of Operation Eagle Claw in 1980. Various operators deployed their CH-53s during international missions, often under

7860-505: The CH-53 were retired by 2008, flown by the U.S. Air Force for combat search and rescue. Overall, the CH-53 was replaced in many roles by the V-22 tilt rotor in U.S. service. 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

7991-762: The Chinese top in a model consisting of contrarotating turkey flight feathers as rotor blades, and in 1784, demonstrated it to the French Academy of Sciences . Sir George Cayley , influenced by a childhood fascination with the Chinese flying top, developed a model of feathers, similar to that of Launoy and Bienvenu, but powered by rubber bands. By the end of the century, he had progressed to using sheets of tin for rotor blades and springs for power. His writings on his experiments and models would become influential on future aviation pioneers. Alphonse Pénaud would later develop coaxial rotor model helicopter toys in 1870, also powered by rubber bands. One of these toys, given as

SECTION 60

#1732780864172

8122-478: The Chinese toy. It was not until the early 1480s, when Italian polymath Leonardo da Vinci created a design for a machine that could be described as an " aerial screw ", that any recorded advancement was made towards vertical flight. His notes suggested that he built small flying models, but there were no indications for any provision to stop the rotor from making the craft rotate. As scientific knowledge increased and became more accepted, people continued to pursue

8253-522: The Chinook could not meet their requirements without numerous expensive changes. The first YCH-53A performed its initial flight at the Sikorsky plant in Stratford, Connecticut , on 14 October 1964, about four months behind schedule. During the previous month, the USMC had already placed an initial production contract for 16 helicopters. Flight trials went more smoothly than expected, helping make up for

8384-736: 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. 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 CH-53G Mittlerer Transporthubschrauber helicopter flew from Speyer on 11 October 1971 and

8515-453: The Gyroplane No. 1 lifted its pilot into the air about 0.6 metres (2 ft) for a minute. The Gyroplane No.   1 proved to be extremely unsteady and required a man at each corner of the airframe to hold it steady. For this reason, the flights of the Gyroplane No.   1 are considered to be the first manned flight of a helicopter, but not a free or untethered flight. That same year, fellow French inventor Paul Cornu designed and built

8646-537: 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,

8777-761: The IDF to land and extract Sayeret commandos on raids and patrols deep behind enemy lines in Lebanon Syria and the greater Middle East. During the 1980s, Israel Aircraft Industries, along with Elbit Systems, commenced a major upgrade program for the IAF Yas'ur fleet. The project, which was completed in 1997, improved the CH-53's avionics and increased its robustness, as well as extending the fleet's operating life by at least two decades. In 1989, several Yas'urs were used to perform firefighting operations on and around Mount Carmel . They performed dozens of low flyovers into

8908-571: The Martian atmosphere is 100 times thinner than Earth's, its two blades spin at close to 3,000 revolutions a minute, approximately 10 times faster than that of a terrestrial helicopter. In 2017, 926 civil helicopters were shipped for $ 3.68 billion, led by Airbus Helicopters with $ 1.87 billion for 369 rotorcraft, Leonardo Helicopters with $ 806 million for 102 (first three-quarters only), Bell Helicopter with $ 696 million for 132, then Robinson Helicopter with $ 161 million for 305. By October 2018,

9039-701: The T64-413 with its further elevated output of 3,925 shp (2,927 kW); 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

9170-705: 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

9301-506: 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 ). 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. During

9432-457: 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. During 2007,

9563-411: The aircraft's general handling characteristics were checked at an altitude of 10,000 feet at a speed of approximately 150 knots. The landing gear was left down throughout the entire flight; takeoff and landing were made with wing and flaps at 10 degrees. Throughout the flight, the aircraft demonstrated smooth response and stable aerodynamic characteristics. At the end of September 1964, the overall program

9694-550: The aircraft's handling properties under low airspeed conditions—it has proved advantageous to conduct tasks that were previously not possible with other aircraft, or were time- or work-intensive to accomplish on the ground. Today, helicopter uses include transportation of people and cargo, military uses, construction, firefighting, search and rescue , tourism , medical transport, law enforcement, agriculture, news and media , and aerial observation , among others. A helicopter used to carry loads connected to long cables or slings

9825-503: 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 rocket, completely destroying the helicopter. The occupants survived the attack with minor to medium injuries. During the 1970s, an initial fleet of six RH-53D Sea Stallions was delivered to the Imperial Iranian Navy (IIN). Following

9956-784: The auspices of NATO or the United Nations , such as for UNSCOM in Iraq, in Kosovo with KFOR , IFOR in Bosnia and Herzegovina, and the ISAF in Afghanistan. While several operators have opted to retain the type into the twenty-first century, many others have opted to supplement or withdraw their Sea Stallions in favor of other platforms, sometimes with the more powerful CH-53E. The CH-53 remains in service with German and Israeli forces, and

10087-466: The aviation industry; and the turboshaft engine for helicopter use, pioneered in December 1951 by the aforementioned Kaman K-225, finally gave helicopters an engine with a large amount of power and a low weight penalty. Turboshafts are also more reliable than piston engines, especially when producing the sustained high levels of power required by a helicopter. The turboshaft engine was able to be scaled to

10218-435: The blades angle forwards or backwards, or left and right, to make the helicopter move in those directions. The anti-torque pedals are located in the same position as the rudder pedals in a fixed-wing aircraft, and serve a similar purpose, namely to control the direction in which the nose of the aircraft is pointed. Application of the pedal in a given direction changes the pitch of the tail rotor blades, increasing or reducing

10349-677: The building of roads. These operations are referred to as longline because of the long, single sling line used to carry the load. In military service helicopters are often useful for delivery of outsized slung loads that would not fit inside ordinary cargo aircraft: artillery pieces, large machinery (field radars, communications gear, electrical generators), or pallets of bulk cargo. In military operations these payloads are often delivered to remote locations made inaccessible by mountainous or riverine terrain, or naval vessels at sea. In electronic news gathering , helicopters have provided aerial views of some major news stories, and have been doing so, from

10480-612: The case of the United States Marine Corps , from further offshore. On 27 January 1961, a series of DOD actions resulted in an agreement where all of the military services would work on the Tri-Service Assault Transport Program under the Navy's Bureau of Naval Weapons (BuWeps) leadership. The original outline had been drawn up as a replacement for the Sikorsky HR2S , with a payload on the order of 10,000 lb (4,500 kg). BuWeps released

10611-406: The cockpit from overhead. The control is called the cyclic because it changes cyclic pitch of the main blades. The result is to tilt the rotor disk in a particular direction, resulting in the helicopter moving in that direction. If the pilot pushes the cyclic forward, the rotor disk tilts forward, and the rotor produces a thrust in the forward direction. If the pilot pushes the cyclic to the side,

10742-470: The cyclic, the collective, the anti-torque pedals, and the throttle. The cyclic control is usually located between the pilot's legs and is commonly called the cyclic stick or just cyclic . On most helicopters, the cyclic is similar to a joystick. However, the Robinson R22 and Robinson R44 have a unique teetering bar cyclic control system and a few helicopters have a cyclic control that descends into

10873-471: The deal, reduced their estimate for the program's development costs by proposing that development could be performed with only two prototypes. Military officials favourably 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. The development program did not go entirely smoothly, due to

11004-536: The early 21st century, as well as recently weaponized utilities such as artillery spotting , aerial bombing and suicide attacks . The English word helicopter is adapted from the French word hélicoptère , coined by Gustave Ponton d'Amécourt in 1861, which originates from the Greek helix ( ἕλιξ ), genitive helikos (ἕλῐκος), "helix, spiral, whirl, convolution" and pteron ( πτερόν ) "wing". In

11135-439: The event was taken by Max Skladanowsky , but it remains lost . In 1885, Thomas Edison was given US$ 1,000 (equivalent to $ 34,000 today) by James Gordon Bennett, Jr. , to conduct experiments towards developing flight. Edison built a helicopter and used the paper for a stock ticker to create guncotton , with which he attempted to power an internal combustion engine. The helicopter was damaged by explosions and one of his workers

11266-549: 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

11397-486: The first half of the 20th century was that the amount of power produced by an engine was not able to overcome the engine's weight in vertical flight. This was overcome in early successful helicopters by using the smallest engines available. When the compact, flat engine was developed, the helicopter industry found a lighter-weight powerplant easily adapted to small helicopters, although radial engines continued to be used for larger helicopters. Turbine engines revolutionized

11528-478: 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. Due to the aircraft's large size and troop capacity, aerial accidents involving CH-53 helicopters have been some of the deadliest helicopter accidents . Data from Deagel.com, U.S. Navy history, International Directory, US Navy Fact File General characteristics Performance Helicopter A helicopter

11659-515: The high operating cost of helicopters cost-effective in ensuring that oil platforms continue to operate. Various companies specialize in this type of operation. NASA developed Ingenuity , a 1.8 kg (4.0 lb) helicopter used to survey Mars (along with a rover). It began service in February 2021 and was retired due to sustained rotor blade damage in January 2024 after 73 sorties. As

11790-480: The idea of vertical flight. In July 1754, Russian Mikhail Lomonosov had developed a small coaxial modeled after the Chinese top but powered by a wound-up spring device and demonstrated it to the Russian Academy of Sciences . It was powered by a spring, and was suggested as a method to lift meteorological instruments. In 1783, Christian de Launoy , and his mechanic , Bienvenu, used a coaxial version of

11921-504: The in-service and stored helicopter fleet of 38,570 with civil or government operators was led Robinson Helicopter with 24.7% followed by Airbus Helicopters with 24.4%, then Bell with 20.5 and Leonardo with 8.4%, Russian Helicopters with 7.7%, Sikorsky Aircraft with 7.2%, MD Helicopters with 3.4% and other with 2.2%. The most widespread model is the piston Robinson R44 with 5,600, then the H125/ AS350 with 3,600 units, followed by

12052-528: 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. 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

12183-662: The lack of an airstrip would make transport via fixed-wing aircraft impossible. The use of transport helicopters to deliver troops as an attack force on an objective is referred to as " air assault ". Unmanned aerial systems (UAS) helicopter systems of varying sizes are developed by companies for military reconnaissance and surveillance duties. Naval forces also use helicopters equipped with dipping sonar for anti-submarine warfare , since they can operate from small ships. Oil companies charter helicopters to move workers and parts quickly to remote drilling sites located at sea or in remote locations. The speed advantage over boats makes

12314-581: The late 1960s. Helicopters have also been used in films, both in front and behind the camera. The largest single non-combat helicopter operation in history was the disaster management operation following the 1986 Chernobyl nuclear disaster . Hundreds of pilots were involved in airdrop and observation missions, making dozens of sorties a day for several months. " Helitack " is the use of helicopters to combat wildland fires . The helicopters are used for aerial firefighting (water bombing) and may be fitted with tanks or carry helibuckets . Helibuckets, such as

12445-555: The limited power did not allow for manned flight. The introduction of the internal combustion engine at the end of the 19th century became the watershed for helicopter development as engines began to be developed and produced that were powerful enough to allow for helicopters able to lift humans. Early helicopter designs utilized custom-built engines or rotary engines designed for airplanes, but these were soon replaced by more powerful automobile engines and radial engines . The single, most-limiting factor of helicopter development during

12576-649: The majority of these were subsequently rebuilt into the MH-53 Pave Low . The visually similar CH-53E Super Stallion is a heavier-lifting improved version of the rotorcraft, designated S-80E by Sikorsky; its third engine makes it more powerful than the Sea Stallion and thus displaced it for the heavy-lift mission. 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. Several export deals for

12707-485: The monorotor design, and coaxial-rotor , tiltrotor and compound helicopters are also all flying today. Four-rotor helicopters ( quadcopters ) were pioneered as early as 1907 in France, and along with other types of multicopters , have been developed mainly for specialized applications such as commercial unmanned aerial vehicles (drones) due to the rapid expansion of drone racing and aerial photography markets in

12838-601: The nearby park, the Parco Forlanini. Emmanuel Dieuaide's steam-powered design featured counter-rotating rotors powered through a hose from a boiler on the ground. In 1887 Parisian inventor, Gustave Trouvé , built and flew a tethered electric model helicopter. In July 1901, the maiden flight of Hermann Ganswindt 's helicopter took place in Berlin-Schöneberg; this was probably the first heavier-than-air motor-driven flight carrying humans. A movie covering

12969-566: The newly formed Army Aviation Corps Regiment 15 based at Rheine and Army Aviation Corps Regiment 25 based at Laupheim . To meet ever more demanding specifications, over time the CH-53G received modifications from 1990 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 1,100 mi (1,800 km) when carrying 36 armed soldiers or

13100-464: The nose to pitch down, with a resultant increase in airspeed and loss of altitude. Aft cyclic will cause the nose to pitch up, slowing the helicopter and causing it to climb. Increasing collective (power) while maintaining a constant airspeed will induce a climb while decreasing collective will cause a descent. Coordinating these two inputs, down collective plus aft cyclic or up collective plus forward cyclic, will result in airspeed changes while maintaining

13231-492: The original engines were replaced by the more powerful T64-100 engines. 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. On 1 January 2013, all Army Aviation Corps CH-53Gs were transferred to

13362-411: The power normally required to be diverted for the tail rotor to be applied fully to the main rotors, increasing the aircraft's power efficiency and lifting capacity. There are several common configurations that use the counter-rotating effect to benefit the rotorcraft: Tip jet designs let the rotor push itself through the air and avoid generating torque. The number, size and type of engine(s) used on

13493-436: The rotor disk tilts to that side and produces thrust in that direction, causing the helicopter to hover sideways. The collective pitch control or collective is located on the left side of the pilot's seat with a settable friction control to prevent inadvertent movement. The collective changes the pitch angle of all the main rotor blades collectively (i.e. all at the same time) and independently of their position. Therefore, if

13624-406: The rotor in cruise, which allows its rotation to be slowed down , thus increasing the maximum speed of the aircraft. The Lockheed AH-56A Cheyenne diverted up to 90% of its engine power to a pusher propeller during forward flight. There are three basic flight conditions for a helicopter: hover, forward flight and the transition between the two. Hovering is the most challenging part of flying

13755-422: The rotor throughout normal flight. The rotor system, or more simply rotor , is the rotating part of a helicopter that generates lift . A rotor system may be mounted horizontally, as main rotors are, providing lift vertically, or it may be mounted vertically, such as a tail rotor, to provide horizontal thrust to counteract torque from the main rotors. The rotor consists of a mast, hub and rotor blades. The mast

13886-470: The rotorcraft could be equipped to facilitate all-weather operations. It shares a somewhat similar fuselage design, albeit on a substantially larger scale, with the Sikorsky S-61R series. 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. To save space, which is normally at

14017-418: The size of the helicopter being designed, so that all but the lightest of helicopter models are powered by turbine engines today. Special jet engines developed to drive the rotor from the rotor tips are referred to as tip jets . Tip jets powered by a remote compressor are referred to as cold tip jets, while those powered by combustion exhaust are referred to as hot tip jets. An example of a cold jet helicopter

14148-483: The skies. Since helicopters can achieve a unique aerial view, they are often used in conjunction with police on the ground to report on suspects' locations and movements. They are often mounted with lighting and heat-sensing equipment for night pursuits. Military forces use attack helicopters to conduct aerial attacks on ground targets. Such helicopters are mounted with missile launchers and miniguns . Transport helicopters are used to ferry troops and supplies where

14279-405: The smoke and flames, dumped 700 tons of water on the fire, and doused it. 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 . During the 2006 Lebanon War , Hezbollah shot down an Israeli CH-53 Yas'ur with an anti-tank missile, killing five air crew members. This

14410-479: The tail rotor, such as the ducted fan (called Fenestron or FANTAIL ) and NOTAR . NOTAR provides anti-torque similar to the way a wing develops lift through the use of the Coandă effect on the tail boom. The use of two or more horizontal rotors turning in opposite directions is another configuration used to counteract the effects of torque on the aircraft without relying on an anti-torque tail rotor. This allows

14541-448: The throttle is to maintain enough engine power to keep the rotor RPM within allowable limits so that the rotor produces enough lift for flight. In single-engine helicopters, the throttle control is a motorcycle-style twist grip mounted on the collective control, while dual-engine helicopters have a power lever for each engine. A compound helicopter has an additional system for thrust and, typically, small stub fixed wings . This offloads

14672-417: The thrust produced by the tail rotor and causing the nose to yaw in the direction of the applied pedal. The pedals mechanically change the pitch of the tail rotor altering the amount of thrust produced. Helicopter rotors are designed to operate in a narrow range of RPM . The throttle controls the power produced by the engine, which is connected to the rotor by a fixed ratio transmission. The purpose of

14803-458: The time lost in development; on 19 November 1964, the type was formally introduced to the general public. Around this time, it received the military designation and name CH-53A Sea Stallion . On 12 September 1966, the first deliveries of the CH-53 to an operational unit occurred. The CH-53A arrived in Vietnam in January 1967 and proved useful, eventually recovering even more downed aircraft than

14934-558: The time, the country was engaged in the War of Attrition , and thus the type was quickly dispatched into combat. Receiving the Hebrew name Yas'ur ( Petrel ), a further 35 helicopter were delivered to fulfil subsequent orders. On 6 August 1970, the first Yas'ur squadron was established. For several decades, the type has served as the primary cargo helicopters of the IAF, being routinely used to carry both troops and heavy equipment. In 1969, during

15065-527: The upper fuselage. Later engines included the T64-1, capable of generating up to 3,080 shp (2,300 kW), and the T64-16, which was rated for up to 3,485 shp (2,599 kW). The HH-53B model featured T64-3 engines, which produced up to 3,080 shp (2,300 kW). The improved CH-53D features uprated engines, initially using the T64-GE-412 that could provide up to 3,695 shp (2,755 kW), then

15196-410: The vastly different operating requirements. Extensive use of titanium was made across its dynamic components, particularly for elements that may have been susceptible to degradation over time due to metal fatigue . Initially, the CH-53 was powered by a pair of General Electric T64-6 turboshaft engines, each of which provided up to 2,850 shaft horsepower (2,130  kW ). These engines were located on

15327-572: The vertical flight he had envisioned. Steam power was popular with other inventors as well. In 1877, the Italian engineer, inventor and aeronautical pioneer Enrico Forlanini developed an unmanned helicopter powered by a steam engine . It rose to a height of 13 meters (43 feet), where it remained for 20 seconds, after a vertical take-off from a park in Milan . Milan has dedicated its city airport to Enrico Forlanini, also named Linate Airport , as well as

15458-495: Was analazed and considered to be "6 to 7 weeks behind schedule". In 1966, while tests were still underway, the Air Force requested a proposal for a production version, the C-142B. Since the Navy had backed out by this time, the Navy carrier compatibility requirement could be eliminated. This dramatically reduced the empty weight. Other changes proposed for this version included a streamlined cockpit, larger fuselage, upgraded engines and simplified engine maintenance. After reviewing

15589-486: Was badly burned. Edison reported that it would take a motor with a ratio of three to four pounds per horsepower produced to be successful, based on his experiments. Ján Bahýľ , a Slovak inventor, adapted the internal combustion engine to power his helicopter model that reached a height of 0.5 meters (1.6 feet) in 1901. On 5 May 1905, his helicopter reached 4 meters (13 feet) in altitude and flew for over 1,500 meters (4,900 feet). In 1908, Edison patented his own design for

15720-615: Was delivered to the Erprobungsstelle der Bundeswehr 61 flight test center at Manching on 1 December 1971. The German Army Aviation Corps received 110 type CH-53Gs, derivatives of the CH-53D, between 1971 and 1975. 108 helicopters were built in Germany by VFW-Fokker. The first flight by a German CH-53G was made in 1971, followed in March 1973 by the delivery of the first machines to Heeresfliegerregiment (HFlgRgt, Army Aviation Corps Regiment) 35 in Mendig , and shortly afterwards to

15851-461: Was essentially a scaled-up S-61R fitted with twin General Electric T64 turboshaft engines and the dynamic system of the S-64 / CH-54 , was selected. On 14 October 1964, the YCH-53A performed its maiden flight ; the first deliveries of production CH-53s to operational units commenced on 12 September 1966. The first combat use of the type occurred during the following year when it was deployed to

15982-411: Was fairly typical for a cargo aircraft , consisting of a large boxy fuselage with a tilted rear area featuring a loading ramp. It had a wingspan of 67 ft (20 m) and was 58 ft (18 m) long overall. The fuselage housed a 30 ft (9.1 m) long, 7.5 ft (2.3 m) wide 7 ft (2.1 m) high cargo area with a somewhat boxy cockpit on the front for the crew of two pilots and

16113-635: 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

16244-508: Was intense, with the Chinook having an advantage because it was being acquired by the United States Army . 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. However, a contract was not immediately forthcoming due to budgetary limitations. The USMC had originally sought to procure four prototypes. However, in light of funding shortfalls, Sikorsky, determined to keep

16375-455: 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 ,

16506-399: Was predicted to have an even higher loading of 10 psi (700 hPa), which they believed would limit it to operations to and from prepared landing pads and was therefore unsuitable for assault operations. The first prototype made its first conventional flight on 29 September 1964, first hover on 29 December 1964, and first transition on 11 January 1965. The first XC-142A was delivered to

16637-491: Was provided by differential clutching of the propellers, while yaw used the ailerons, which were in the airflow. For pitch control the aircraft featured a separate tail rotor, oriented horizontally to lift the tail, as opposed to the more conventional anti-torque rotors on helicopters that are mounted vertically. When on the ground, the tail rotor folded against the tail to avoid being damaged during loading. The wing could be rotated to 100 degrees, past vertical, in order to hover in

16768-421: 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. Based upon experience gained from the intense combat of the then-recently fought Six-Day War , the delegation opted to favour the CH-53. On 2 October 1969, the first S-65C-3 (CH-53D) helicopters were delivered to Israel of an initial order of seven. At

16899-409: 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;

17030-408: Was required for safe VTOL operations, and gave the aircraft excellent all-around performance which included a maximum speed of over 400 mph (640 km/h), making it one of the fastest VTOL transport aircraft of the era. The aircraft never proceeded beyond the prototype stage. Five XC-142As were built during the 1960s. The flight, made on the #2 aircraft, was 38 minutes in length, during which

17161-558: 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

#171828