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Boeing Vertol CH-46 Sea Knight - United States, 1964

Detailing the development and operational history of the Boeing Vertol CH-46 Sea Knight Medium-Lift, Tandem Rotor Transport Helicopter.

 Entry last updated on 4/25/2016; Authored by Staff Writer; Content ¬©

  Boeing Vertol CH-46 Sea Knight  
Picture of Boeing Vertol CH-46 Sea Knight

The Boeing Vertol CH-46 Sea Knight is to the United States Marine Corps what the CH-47 Chinook is to the United States Army.

The CH-46 Sea Knight is similar in design and role to the CH-47 Chinook series of transport helicopters. Both offer up unobstructed access to the aircraft by keeping engine components mounted above the design. Both also utilize the patented tandem three-blade rotor design that is most closely associated with the Chinook. Despite these similarities, the Chinook is the larger of the two designs and is the primary workhorse for the US Army whereas the Sea Knight serves the US Marine Corps and, to a degree, the United States Navy.

The CH-46 utilizes two Lycoming turboshaft engines to drive the powerful main rotor blades. Crew accommodations amount to two or three standard personnel with spacing in the cabin for an additional 15-25 troops and 15 stretcher patients. The Sea Knight, like its Chinook counterpart, can also carry external sling loads if need be.

The CH-46 was designed from the Model 107 which was actually evaluated by the US Army through three YCH-1A designated prototypes. Though the Army elected to take the larger C-47, which would become the Chinook, the US Marine Corps accepted their CH-46's as the Sea Knight in 1961 to replace their aging UH-34 series. By 1964, deliveries were in full swing and the CH-46 entered service. Along with USMC use, the US Navy also procured several Sea Knights for sea-borne ship replenishment duty.

The CH-47 saw several variants derived from initial models and service experience, each differing in avionics upgrades, subtle redesigns and powerplant changes. Canada accepted the CH-46 as the "Voyageur" and the "Labrador" to fill roles in search and rescue and transport respectively. Additionally, the CH-46 has appeared with Japanese forces as the KV 107 model series in various roles and with Sweden as the HKP-4 series.

Picture of the Boeing Vertol CH-46 Sea Knight
Picture of the Boeing Vertol CH-46 Sea Knight

Boeing Vertol CH-46E Sea Knight Specifications

Service Year: 1964
Type: Medium-Lift, Tandem Rotor Transport Helicopter
National Origin: United States
Manufacturer(s): Boeing Vertol - USA
Total Production: 524

Structural (Crew, Dimensions, Weights)

Operating Crew (Typical): 3 + 25
Overall Length: 44.82 feet (13.66 meters)
Overall Height: 16.70 feet (5.09 meters)

Weight (Empty): 11,585 lb (5,255 kg)
Weight (MTOW): 24,299 lb (11,022 kg)

Power / Performance (Engine Type, Top Speed)

Engine: 2 x General Electric T58-GE-16 turboshaft engines developing 1,870 horsepower and driving tandem three-blade rotor systems.

Maximum Speed: 144 knots (166 mph; 267 kph)
Maximum Range: 599 nautical miles (690 miles; 1,110 km)
Service Ceiling: 9,498 feet (2,895 meters; 1.80 miles)
Rate-of-Climb: 1,715 feet-per-minute (523 m/min)

Armament / Mission Payload


Global Operators (Customers, Users)

Canada; Japan; Sweden; Saudi Arabia; Sweden; Thailand; United States

Model Variants

Model 107 - Vertol Prototype Model; fitted with 2 x Lycoming T53 turboshaft engines.
YCH-1A - US Army Prototype Evaluation Model designation of which three were produced.
HRB-1 - Initial Production Designation for US Marine Corps, later redesignated to CH-46 after 1962.
CH-46A - Initial Production Designation from HRB-1 after 1962; 107 produced for US Marine Corps usage; fitted with General Electric T58-GE-8 turboshaft engines.
UH-46A - Similar to the CH-46A but for US Navy use; 14 such delivered.
CH-46D - USMC model fitted with T-58-GE-10 powerplants.
UH-46D - US Navy model similar to CH-46D USMC model.
CH-46E - Upgraded CH-46D and CH-46F models; fitted with T58-GE-16 powerplants; improved crew survivability features.
CH-46F - Improved avionics
CH-113 "Labrador" - Canadian CH-46A search and rescue models.
CH-113A "Voyageur" - Canadian CH-46A transport models.
HKP-4 - Swedish variant fitted with Rolls-Royce powerplants.
KV 107 - Japan license-produced Model 107 series of various role types.

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