Development of the Sea Knight, which was originally designated by the firm as theVertol Model 107, commenced during 1956. It was envisioned as a successor to the first generation of rotorcraft, such as theH-21 "Flying Banana", that had been powered bypiston engines; in its place, theV-107 made use of the emergent turboshaft engine. On 22 April 1958, the V-107 prototype performed itsmaiden flight. During June 1958, the US Army awarded a contract for the construction of ten production-standard aircraft, designated as theYHC-1A, based on the V-107; this initial order was later cut down to three YHC-1As. During 1961, theUS Marine Corps (USMC), which had been studying its requirements for a medium-lift, twin-turbine cargo/troop assault helicopter, selected Boeing Vertol'sModel 107M as the basis from which to manufacture a suitable rotorcraft to meet their needs. Known colloquially as the "Phrog" and formally as the "Sea Knight", it was operated across all US Marine Corps' operational environments between its introduction during theVietnam War and its frontline retirement during 2014.
The Sea Knight was operated by the USMC to provide all-weather, day-or-night assault transport of combat troops, supplies and equipment until it was replaced by theMV-22 Osprey during the 2010s. The USMC also used the helicopter forcombat support,search and rescue (SAR),casualty evacuation and Tactical Recovery of Aircraft and Personnel (TRAP). The Sea Knight also functioned as theUS Navy's standard medium-liftutility helicopter prior to the type being phased out of service in favor of theMH-60S Knighthawk during the early 2000s. Several overseas operators acquired the rotorcraft as well.Canada operated the Sea Knight, designated asCH-113; the type was used predominantly in the SAR role until 2004. Other export customers for the type includedJapan,Sweden, andSaudi Arabia. The commercial version of the rotorcraft is theBV 107-II, commonly referred to simply as the "Vertol". The Sea Knight is an amphibious helicopter, able to land directly on calm water and float, but only for a few hours.
During the 1940s and 1950s, American rotorcraft manufacturerPiasecki Helicopter emerged as a pioneering developer oftandem-rotor helicopters; perhaps the most famous of these being the piston-poweredH-21 "Flying Banana", an early utility and transport helicopter. During 1955, Piasecki was officially renamed as Vertol Corporation (standing forvertical take-off and landing); it was around this time that work commenced on the development of a new generation of tandem rotor helicopter. During 1956, the new design received the internal company designation ofVertol Model 107, or simplyV-107; this rotorcraft differed from its predecessors by harnessing the newly developedturboshaft engine instead of piston-based counterparts. During that year, construction of a prototype, powered by a pair ofLycoming T53 turboshaft engines, each one being capable of producing 877 shp (640 kW), commenced.[2]
V-107 prototype in 1961
On 22 April 1958, the V-107 prototype performed itsmaiden flight.[3] In order to garner publicity for the newly developed rotorcraft, it was decided to use the prototype to conduct a series of publicised flight demonstrations during a tour across the United States and several overseas nations. During June 1958, it was announced that the U.S. Army had awarded a contract to Vertol for the construction of ten production-standard aircraft based on the V-107, which were designatedYHC-1A.[4] However, this order was later decreased to three helicopters; according to aviation author Jay P. Spenser, the cutback had been enacted in order that the U.S. Army would be able to divert funds for the development of the rivalV-114 helicopter, which was also a turbine-powered tandem rotor design but substantially larger than the V-107.[4] All of the U.S. Army's three YHC-1As were powered by pairs ofGE-T-58 engines. During August 1959, the first YHC-1A-model rotorcraft conducted its first flight; independently, it was shortly followed by the maiden flight of an improved model intended for the commercial and export markets, designated107-II.[1]
During 1960, theU.S. Marine Corps evolved a requirement for a medium-lift, twin-turbine troop/cargo assault helicopter to replace the various piston-engined types that were then in widespread use with the service.[5] That same year, American aviation companyBoeing acquired Vertol, after which the group was consequently renamedBoeing Vertol.[4] Following a competition between several competing designs, during early 1961, it was announced that Boeing Vertol had been selected to manufacture its model 107M for the U.S. Marine Corps, where it was designatedHRB-1.[1] During 1962, theU.S. Air Force placed its own order for 12XCH-46B Sea Knight helicopters, which used theXH-49A designation; however, the service later decided to cancel the order due to delays in its delivery; instead, the U.S. Air Force opted to procure the rivalSikorsky S-61R in its place.[citation needed]
Following the Sea Knight's first flight in August 1962, the military designation was changed toCH-46A. During November 1964, the introduction of the Marines' CH-46A and the Navy's UH-46As commenced. The UH-46A variant was a modified version of the rotorcraft to perform thevertical replenishment mission.[1] The CH-46A was equipped with a pair of T58-GE8-8B turboshaft engines, each being rated at 1,250 shp (930 kW); these allowed the Sea Knight to carry up to 17 passengers or a maximum of 4,000 pounds (1,815 kg) of cargo.[6]
During 1966, production of the improvedCH-46D commenced with deliveries following shortly thereafter. This model featured various improvements, including modifiedrotor blades and the adoption of more powerful T58-GE-10 turboshaft engines,[1] rated at 1,400 shp (1,040 kW) each. The increased power of these new engines allowed the CH-46D to carry an increased payload, such as up to 25 troops or a maximum of 7,000 pounds (3,180 kg) of cargo.[6] During late 1967, the improved model was introduced to theVietnam theater, where it supplemented the U.S. Marine Corps' existing CH-46A fleet, which had proven to be relatively unreliable and problematic in service.[7] Along with the USMC's CH-46Ds, the U.S. Navy also acquired a small number of UH-46Ds for ship resupply purposes.[8] In addition, approximately 33 CH-46As were progressively re-manufactured to the CH-46D standard.[6]
Formation of HH-46Es, used for search and rescue
Between 1968 and 1971, the U.S. Marine Corps received a number of CH-46F standard rotorcraft. This model retained the T58-GE-10 engines used on the CH-46D while featuring revised avionics and featured a number of other modifications. The CH-46F was the final production model of the type.[1] During its service life, the Sea Knight received a variety of upgrades and modifications. Over time, the majority of the U.S. Marine Corps' Sea Knights were upgraded to the improved CH-46E standard. This model featuredfiberglass rotor blades, reinforcement measures throughout the airframe, along with the refitting of further uprated T58-GE-16 engines, capable of producing 1,870 shp (1,390 kW) each; in addition, several CH-46Es were modified to double their maximum fuel capacity.[6] Starting in the mid-1990s, the Dynamic Component Upgrade (DCU) programmes was enacted, focusing on the implementation of strengthened drive systems and modified rotor controls.[citation needed]
The commercial variant, theBV 107-II, was first ordered byNew York Airways during 1960. During July 1962, they took delivery of their first three aircraft, which was configured to seat up to 25 passengers.[5] During 1965, Boeing Vertol sold the manufacturing rights of the 107 to JapaneseconglomerateKawasaki Heavy Industries. Under this arrangement, all Model 107 civilian and military aircraftbuilt in Japan were referred to by theKV 107 designation.[5] On 15 December 2006,Columbia Helicopters, Inc acquired thetype certificate for the BV 107-II, and with the help of Piasecki eventually developed an original design, theModel 107-III, remanufactured from older airframes.[9] This model features new manufactured CT58-GE-16 engines, the commercial version of the upgraded engines used for the CH-46E as well as modernized avionics including a glass cockpit.[9]
Sea Knight carrying supplies, with its tricycle landing gear silhouetted
TheBoeing Vertol CH-46 Sea Knight is a medium-lift tandem-rotortransport helicopter, furnished with a set of counter-rotating main rotors in a tandem-rotor configuration. It was typically powered by a pair of General Electric T58 turboshaft engines, which were mounted on each side of the rear rotor pedestal; power to the forward rotor was transferred from the rear-mounted engines via adrive shaft. For redundancy, both engines are coupled so that either one would be capable of powering both of the main rotors in the event of a single engine failure or a similar emergency situation. Each of the rotors feature three blades, which can be folded to better facilitate storage and naval operations.[6] The CH-46 features a fixedtricycle landing gear, complete with twin wheels on all three legs of the landing gear; this configuration results in a nose-up stance, helping to facilitate cargo loading and unloading. Two of the main landing gear were installed within protruding rearsponsons; the free interior space of the sponsons are also used to house fuel tanks, possessing a total capacity of 350 US gallons (1,438 L).[6]
Looking out from a cockpit of a CH-46, at another
The interior of the CH-46 was largely taken up by its cargo bay, complete with a rear loading ramp that could be removed or left open in flight for the carriage of extended cargoes or for parachute drops. Various furnishings were normally provided to aid in its use as a utility rotorcraft, such as an internalwinch mounted within the forward cabin, which can be used to assisting loading by pulling external cargo onpallets into the aircraft via the ramp and rollers, and an optionally-attached belly-mountedcargo hook, which would be usually rated at 10,000 lb (4,500 kg) for carrying cargoes externally underneath the Sea Knight; despite the hook having been rated at 10,000 lb (4,500 kg), this was safety restricted to less payload as they got older. When operated in a typical configuration, the CH-46 would usually be operated by a crew of three; a larger crew could be accommodated when required, which would be dependent upon mission specifics. For example, asearch and rescue (SAR) variant would usually carry a crew of five (Pilot, Co-Pilot, Crew Chief, Swimmer, and Medic) to facilitate all aspects of such operations. For self-defense, apintle-mounted 0.50 in (12.7 mm)M2 Browningmachine gun could be mounted on each side of the helicopter.[6] Service in southeast Asia resulted in the addition ofarmor along with the machine guns.[1]
The CH-46 was a partiallyamphibious helicopter, and could land directly on water and rest for up to two hours[10] in calm water.[11] The rearsponsons hold two of the three landing gear units as well as self-sealing fuel tanks.[10]
Known colloquially as the "Phrog", the Sea Knight was used in all U.S. Marine operational environments between its introduction during the Vietnam War and its retirement in 2015.[12] The type's longevity and reputation for reliability led to mantras such as "phrogs phorever" and "never trust a helicopter under 30".[13] CH-46s transported personnel, evacuated wounded, supplied forward arming and refueling points (FARP), performed vertical replenishment, search and rescue, recovered downed aircraft and crews and other tasks.
A flaming Marine CH-46 of HMM-265, after being hit by enemy AAA fire in "Helicopter Valley", 15 July 1966[14]
During the Vietnam War, the CH-46 was one of the prime US Marine troop transport helicopters in the theater, slotting between the smallerBell UH-1 Iroquois and largerSikorsky CH-53 Sea Stallion and progressively replacing theUH-34. CH-46 operations were plagued by major technical problems; the engines, being prone toforeign object damage (FOD) from debris being ingested when hovering close to the ground and subsequently suffering acompressor stall, had a lifespan as low as 85 flight hours; on 21 July 1966, all CH-46s were grounded until more efficient filters had been fitted.[15]
On 3 May 1967, a CH-46D atMarine Corps Air Facility Santa Ana crashed, killing all four members of the crew. Within three days the accident investigators had determined that the mounting brackets of the main transmission had failed, allowing the front and rear overlapping rotors to intermesh. All CH-46s were temporarily grounded for inspection. On 13 May, a CH-46A crashed off the coast of Vietnam when the tail pylon containing the engines, main transmission and aft rotors broke off in flight. All four crew members were killed. On 20 June, another CH-46A crashed, though two of the four-man crew survived. Once again, even though the aircraft was not recovered from the water, failure of some sort in the rear pylon was suspected. On 30 June a CH-46D at Santa Ana crashed when a rotor blade separated from the aircraft, all three of the crew survived. As a result of this latest accident, all CH-46Ds were immediately grounded, but the CH-46As continued flying. On 3 July another CH-46A crashed in Vietnam, killing all four Marines of its crew. The cause of the crash again was traced to failure of the main transmission.[16]: 121–2
On 31 August 1967, a CH-46A on a medical evacuation mission toUSS Tripoli disintegrated in midair killing all its occupants. The following day another CH-46A experienced a similar incident atMarble Mountain Air Facility leading to the type being grounded for all except emergency situations and cutting Marine airlift capacity in half.[17]: 170 An investigation conducted by a joint Naval Air Systems Command/Boeing Vertol accident investigation team revealed that structural failures were occurring in the area of the rear pylon resulting in the rear rotor tearing off in flight and may have been the cause of several earlier losses. The team recommended structural and systems modifications to reinforce the rear rotor mount as well as installation of an indicator to detect excessive strain on critical parts of the aircraft. 80 CH-46As were shipped toMarine Corps Air Station Futenma,Okinawa where they received the necessary modifications by a combined force of Marine and Boeing Vertol personnel. The modified CH-46As began returning to service in December 1967 and all had been returned to service by February 1968.[17]: 210–1 [16]: 123
During the 1972Easter Offensive, Sea Knights saw heavy use to convey US andSouth Vietnamese ground forces to and around the front lines.[18] Marine CH-46s participated inOperation Frequent Wind, the evacuation ofSaigon, in April 1975 and the last helicopter to leave the roof of theUS embassy was a CH-46 ofHMM-164.[19] By the end of US military operations in Vietnam, over a hundred Sea Knights had been lost to enemy fire.[20]
Soldiers from the2nd Ranger Battalion board a Marine Corps CH-46E helicopter fromVMM-261 before the rescue of American students at St. George's University during Operation Urgent Fury in 1983.
In February 1968 theMarine Corps Development and Education Command obtained several CH-46s to perform herbicide dissemination tests using HIDAL (Helicopter, Insecticide Dispersal Apparatus, Liquid) systems; testing indicated the need for redesign and further study.[21] Tandem-rotor helicopters were often used to transport nuclear warheads; the CH-46A was evaluated to deploy NavalSpecial Forces with theSpecial Atomic Demolition Munition (SADM).[22] Nuclear Weapon Accident Exercise 1983 (NUWAX-83), simulating the crash of a Navy CH-46E carrying 3 nuclear warheads, was conducted at theNevada Test Site on behalf of several federal agencies; the exercise, which used real radiological agents, was depicted in aDefense Nuclear Agency-produced documentary.[23]
CH-46E Sea Knights were also used by the U.S. Marine Corps during the2003 invasion of Iraq. In one incident on 1 April 2003, Marine CH-46Es and CH-53Es carried U.S. Army Rangers and Special Operations troops on an extraction mission for captured Army PrivateJessica Lynch from an Iraqi hospital.[24] During the subsequent occupation of Iraq and counter-insurgency operations, the CH-46E was heavily used in the CASEVAC role, being required to maintain 24/7 availability regardless of conditions.[25] According to authors Williamson Murray and Robert H Scales, the Sea Knight displayed serious reliability and maintenance problems during its deployment to Iraq, as well as "limited lift capabilities".[26] Following the loss of numerous US helicopters in the Iraqi theatre, the Marines opted to equip their CH-46s with more advanced anti-missile countermeasures.[27]
The U.S. Navy retired the type on 24 September 2004, replacing it with theMH-60S Seahawk;[28] the Marine Corps maintained its fleet as theMV-22 Osprey was fielded.[29] In March 2006 Marine Medium Helicopter Squadron 263 (HMM-263) was deactivated and redesignatedVMM-263 to serve as the first MV-22 squadron.[30] The replacement process continued through the other medium helicopter squadrons into 2014. On 5 October 2014, the Sea Knight performed its final service flight with the U.S. Marine Corps atMarine Corps Air Station Miramar.HMM-364 was the last squadron to use it outside the United States, landing it aboardUSS America on her maiden transit. On 9 April 2015, the CH-46 was retired by theMarine Medium Helicopter Training Squadron 164, the last Marine Corps squadron to transition to the MV-22.[31][32] The USMC retired the CH-46 on 1 August 2015 in a ceremony at theUdvar-Hazy Center near Washington DC.[12]
Beginning in April 2011 the Navy'sFleet Readiness Center East began refurbishing retired USMC CH-46Es for service with theUnited States Department of State Air Wing.[33] A number of CH-46s fromHMX-1 were transferred to the Air Wing in late 2014.[34] In Afghanistan the CH-46s were used by Embassy Air for secure transport of State Department personnel. The CH-46s were equipped with missile warning sensors and flare dispensers and could be armed with M240D or M2 Browning machine guns.[35] A report in September 2019 by theState Department Inspector General found that a seat on a CH-46 for a seven-minute flight cost US$1,500 (~$1,763 in 2023).[36]
Seven of the State Department Air Wing CH-46s took part in the2021 Kabul Airlift. Prior to the complete withdrawal of U.S. forces, all seven were rendered unusable and abandoned atKabul International Airport and are seen in many videos and pictures online. One of the CH-46s that was abandoned (BuNo 154038, c/n 2389) also took part inOperation Frequent Wind 46 years earlier. The U.S. State Department drew criticism for leaving behind the aircraft. Commenting on the issue, the U.S. State Department claimed that the helicopters were already being phased out of State Department Air Wing due to their age and the inability to support them. The seven CH-46s left behind were the only U.S. State Department aircraft left behind at Kabul International Airport.[37]
CH-113 Labrador landing on "The Clapper", asea stack off the tip ofBell Island in Newfoundland
TheRoyal Canadian Air Force procured six CH-113 Labrador helicopters for the SAR role and theCanadian Army acquired 12 of the similar CH-113A Voyageur for the medium-lift transport role. The RCAF Labradors were delivered first with the first one entering service on 11 October 1963.[38][39] When the larger CH-147 Chinook was procured by theCanadian Forces in the mid-1970s, the Voyageur fleet was converted to Labrador specifications to undertake SAR missions. The refurbished Voyageurs were re-designated as CH-113A Labradors, thus a total of 15 Labradors were ultimately in service.[39]
The Labrador was fitted with a watertight hull for marine landings, a 5,000 kilogram cargo hook and an external rescue hoist mounted over the right front door. It featured a 1,110 kilometer flying range, emergency medical equipment and an 18-person passenger capacity.[39] In multiple instances throughout the 1970s and 1980s, this increased range provided the capability of the CH-113 to provide assistance toU.S. Coast Guard (USCG) missions or perform long range medevacs over distances the USCG helicopters at the time simply could not reach.[40]
In 1981, a mid-life upgrade of the fleet was carried out byBoeing Canada inArnprior, Ontario. Known as the SAR-CUP (Search and Rescue Capability Upgrade Program), the refit scheme included new instrumentation, a nose-mounted weather radar, a tail-mounted auxiliary power unit, a new high-speed rescue hoist mounted over the side door and front-mounted searchlights. A total of six CH-113s and five CH-113As were upgraded with the last delivered in 1984. Nonetheless, as a search and rescue helicopter it endured heavy use and hostile weather conditions; which had begun to take their toll on the Labrador fleet by the 1990s, resulting in increasing maintenance costs and the need for prompt replacement.[39]
In 1992, it was announced that the Labradors were to be replaced by 15 new helicopters, a variant of theAgustaWestland EH101, designatedCH-149 Chimo. The order was subsequently cancelled by theJean ChrétienLiberal government in 1993, resulting in cancellation penalties, as well as extending the service life of the Labrador fleet. However, in 1998, a CH-113 fromCFB Greenwood crashed on Quebec'sGaspé Peninsula while returning from a SAR mission, resulting in the deaths of all crewmembers on board. The crash placed pressure upon the government to procure a replacement, thus an order was placed with the manufacturers of the EH101 for 15 aircraft to perform the search-and-rescue mission, designatedCH-149 Cormorant. CH-149 deliveries began in 2003, allowing the last CH-113 to be retired in 2004.[39] In October 2005Columbia Helicopters ofAurora, Oregon purchased eight of the retired CH-113 Labradors to add to their fleet of 15 Vertol 107-II helicopters.[41]
In 1963, Sweden procured ten UH-46Bs from the US as a transport and anti-submarine helicopter for theSwedish Armed Forces, designated Hkp 4A. In 1973, a further eight Kawasaki-built KV-107s, which were accordingly designated Hkp 4B, were acquired to replace the older Piasecki H-21. During the Cold War, the fleet's primary missions were anti-submarine warfare and troop transportation. They were also frequently employed in the search and rescue role, most famously during the rescue operation of theMSEstonia after itsank in the Baltic Sea on 28 September 1994. In the 1980s, the Hkp 4A was phased out, having been replaced by theEurocopter AS332 Super Puma; the later Kawasaki-built Sea Knights continued in operational service until 2011, they were replaced by theUH-60 Black Hawk andNH90.
In December 2006, Columbia Helicopters purchased the type certificate of the Model 107 from Boeing, with the aim of eventually producing new-build aircraft themselves.[48] In 2023, Columbia Helicopters began a program of purchasing older Model 107-II and CH-46E airframes, and refurbishing them into Model 107-IIs for sale.[49][50] Columbia Helicopters has also updated old airframes into theModel 107-III.[9]
Company model number for basic prototype, one built.
Model 107-II
Commercial airline helicopter. All subsequent commercial aircraft were produced as BV 107-II-2, two built as Boeing Vertol prototypes, five sold to New York Airways, ten supplied to Kawasaki as sub-assemblies or as parts. The second prototype was later rebuilt into a Sea Knight replacement for a lost unit in the Swedish navy she was named Y64 in Swedish service.[citation needed]
Model 107-III
Newest variant, codeveloped by Piasecki and Columbia Helicopters following Columbia's purchase of the type certificate in 2006. Made from surviving 107-II and CH-46E airframes from both Boeing and Kawasaki, purchased primarily from foreign militaries, then remanufactured into -III models.[9] These were intended to begin sales by the end of 2024, but as of 2025 are still listed as upcoming on Columbia's website.[9][51] Features new manufactured CT58-GE-16 engines, the commercial version of the upgraded engines used for the CH-46E as well as modernized avionics including a glass cockpit.[9]
Model 107M
Company model number for military transport of BV-107/II-2 for theU.S. Marine Corps.
YHC-1A
Vertol Model 107 for test and evaluation by theUnited States Army. Adopted by the U.S. Marine Corps as the HRB-1. Later redesignatedYCH-46C, three built.
Medium-lift assault and cargo transport and SAR helicopter for the USMC, fitted with two 1,250 shp (935 kW) General Electric T58-GE-8 turboshaft engines. Previously designated HRB-1. 160 built for USMC, one static airframe.
UH-46A
Medium-lift utility transport helicopter for theUnited States Navy. Similar to the CH-46A. 14 built.
HH-46A
Approximately 50 CH-46As were converted into SAR helicopters for the United States Navy base rescue role.
RH-46A
Planned conversion of CH-46As into minesweeping helicopters for the US Navy, none converted. NineSH-3As were converted to the RH-3A configuration instead.
UH-46B
Development of the CH-46A to specification HX/H2 for theUnited States Air Force; 12 ordered in 1962, cancelled and Sikorsky S-61R / CH-3C ordered instead.
YCH-46C
YHC-1A redesignated in 1962.United States Army retained two,NASA used one for vertical autonomous landing trials (VALT).
Medium-lift assault and cargo transport helicopter for the USMC, fitted with two 1,400 shp (1,044 kW) General Electric T58-GE-10 turboshaft engines. 266 built.
HH-46D
Surviving HH-46A were upgraded and a small number of UH-46Ds were converted into SAR helicopters. SAR upgrades included the addition of an external rescue hoist near the front crew door and an 18-inch X 18-inch Doppler RADAR system located behind the nose landing gear, which provided for automatic, day/night, over-water hovering capability for at sea rescue. Additionally a "Loud Hailer" was installed opposite the crew entrance door for communicating with downed aviators on the ground or in the water.
Medium-lift utility transport helicopter for the US Navy combat supply role. Similar to the CH-46D. Ten built and one conversion from CH-46D.
CH-46E
Approximately 275 -A, -D, and -F airframes were updated to CH-46E standards with improved avionics, hydraulics, drive train and upgraded T58-GE-16 and T58-GE-16/A engines.
HH-46D used for SAR by the USMC
HH-46E
Three CH-46Es were converted into SAR helicopters for Marine Transport Squadron One (VMR-1) at MCAS Cherry Point.[52]
CH-46F
Improved version of CH-46D, electrical distribution, com/nav update BUNO 154845-157726. Last production model in the United States. 174 built, later reverted to CH-46E.[citation needed]
VH-46F
Unofficial designation of standard CH-46F used by HMX-1 as VIP support transport helicopter.
CH-46X
Replacement helicopter based on theBoeing Model 360, this Advance Technology Demonstrator from the 1980s never entered production. The aircraft relied heavily on composites for its construction and had a beefier drive train to handle the twin Avco-Lycoming AL5512 engines (4,200 shp).[53]
Search and rescue version of the Model 107-II-9 for the Royal Canadian Air Force
CH-113A Voyageur
Assault and utility transport version of the Model 107-II-28 for the Canadian Army. Later converted to CH-113A Labrador when the Canadian Forces acquired the CH-47 Chinook
Boeing-Vertol civil prototype in service with theSwedish Navy as an HKP 4B, 1981
HKP 4A
Boeing Vertol 107-II-14, used originally by Air Force for search and rescue, ten built
HKP 4B
Boeing Vertol 107-II-15, mine-layer/antisubmarine warfare/search and rescue helicopter for Navy, three built and one conversion from Boeing-Vertol civil prototype
HKP 4C
Kawasaki KV-107-II-16, advanced mine-layer/ASW/SAR helicopter for Navy, eight built
HKP 4D
Rebuilt HKP 4A for Navy as SAR/ASW helicopter, four conversions
On 14 October 1963 New York Airways Flight 600, a Boeing Vertol 107, registration N6673D, crashed shortly after takeoff fromIdlewild Airport (now JFK) en route toNewark via Wall Street. All three passengers and all three crew members died. The accident was caused by mechanical failure due to contaminated lubricants.[82][83]
On 15 July 1966 in the Vietnam War duringOperation Hastings, two CH-46As ofHMM-164 collided at Landing Zone Crow while another, crashed into a tree avoiding the first two, resulting in 2 Marines killed. Another CH-46 ofHMM-265 was shot down at the LZ later that day resulting in a further 13 Marine deaths.[84]
On 4 June 1968, CH-46D BuNo 152533 ofHMM-165 was hit by anti-aircraft fire atLanding Zone Loon and crashed killing 13 Marines.[85]
On 14 March 1969, CH-46D BuNo 154841 ofHMM-161 was hit by aB-40 rocket as it conducted a resupply and medevac mission atLanding Zone Sierra, killing 12 Marines and 1 Navy corpsman.[86]
On 10 May 1996, a CH-46E collided in mid-air with anBell AH-1W attack helicopter, killing fourteen (twelve Marines, one Navy sailor, and one Army soldier) aboard the two helicopters. The pilots of the CH-46E were injured. Both helicopters, ofHMM-266, were operating fromUSSSaipan and were participating in Operation Purple Star, a joint exercise involving troops from the U.S. and the UK atCamp Lejeune, North Carolina.[87][88][89][90]
On 2 October 1998, a CH-113 Labrador crashed nearMarsoui, Quebec, after an inflight fire. All six crewmembers were killed.[91]
On 9 December 1999, a CH-46D Sea Knight BuNo 154790 ofHMM-166 crashed during a boarding exercise off the coast of San Diego, California, killing seven U.S. Marines. The pilot landed the CH-46 short on the deck of theUSNSPecos, causing the left rear tire and strut to become entangled in the safety netting at the back of the ship, which caused it to plunge into the ocean.[92]
153962, 154853, 155316, 154810, 157678, 157682 – National United States Armed Forces Museum in Houston, Texas displays four Marine Corps CH-46Es in various configurations including an HMX-1 aircraft and an HH-46E "Pedro" configured for search and rescue '01' from VMR-1 Cherry Point MCAS, NC.[citation needed]
150954 –USSMidway Museum in San Diego, California displays HH-46A (c/n 2040) as U.S. Navy SA-46 ofHC-3 on one side and VR-46 ofHC-11 on the other.[citation needed]
153986 –National Museum of the Marine CorpsQuantico, Virginia has a walk-through exhibit containing the rear half of a CH-46D displayed as the former BuNo 153986 (c/n 2337) YK-13 fromHMM-364 with their logo, The Purple Fox.[102] The front half of the aircraft was used as a training aid display for HMX-1.[103][104]
Data from The International Directory of Military Aircraft, 2002/2003,[113] The Complete Encyclopedia of World Aircraft : Boeing Vertol Model 107 (H-46 Sea Knight),[3] Encyclopedia of world military aircraft : Volume One[114]
General characteristics
Crew: 5: two pilots, one crew chief, one aerial gunner/observer, one tail gunner
Capacity:
24 troopsor
15 stretchers and two attendantsor
7,000 lb (3,200 kg)
Length: 44 ft 10 in (13.67 m) (fuselage)
83 ft 4 in (25.40 m) (rotors turning)
Height: 16 ft 9 in (5.11 m) to top of rear rotor head
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This article incorporates text from this source, which is in thepublic domain:Fails, William (1978).Marines and Helicopters 1962-1973(PDF). History and Museums Division United States Marine Corps.ISBN 978-1482313598.Archived(PDF) from the original on 2 April 2021.
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