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 ©www.MilitaryFactory.com
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.