UH-46 Sea Knight

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DEPARTMENT OF THE NAVY -- NAVAL HISTORICAL CENTER
805 Kidder Breese SE -- WASHINGTON NAVY YARD
WASHINGTON DC 20374-5060

CH-46 and UH-46 SEA KNIGHT

CH-46 SEA KNIGHT

Fuselage length: 45 feet, 3 inches
Overall length: 84 feet, 4 inches
Weight: empty: 12,112 pounds

loaded: 23,300 pounds
Speed: maximum: 166 mph

cruise: 140 mph
Range: 160 nautical miles

ferry range: 620 nautical miles
Power plant: two GE T58-GE-16 turboshaft engines
Crew: two pilots, one crewman
Contractor: Boeing Vertol
Drawings for a CH-46E (Download as a .pdf file)

UH-46 SEA KNIGHT

Fuselage length: 45 feet
Length: 84 feet
Height: 17 feet
Weight, gross: 23,000 pounds
Speed: 165 mph
Ceiling: 14,000 feet
Range: 206 nautical miles

ferry range: 774 nautical miles
Power plant: two GE T58-GE-16 turboshaft engines
Crew: three
Contractor: Boeing Vertol

Drawings for an H-46D (download as a .pdf file)

Readily identified among current Navy and Marine Corps helicopters are the H-46 series Sea Knights, with their tandem rotor configuration setting them apart from the single rotor design of other Navy/Marine helos. Tandem rotors have been a feature of all production helos built by Boeing/Vertol, and its original predecessor company, Piasecki.

In 1958, Vertol completed a company sponsored prototype of a new helicopter design, powered by two Lycoming T-53 turbine engines for potential military or civilian use. The 107 first flew in April, exhibiting most of the basic configuration characteristics to be found in all of its 107-series successors. The Army ordered three YHC-1As which were developed as GE-T-58-powered military evaluation vehicles under a Bureau of Aeronautics contract. First flying in August 1959, the YHC-1As were followed by an improved commercial/export model, the 107-11.

During 1960, the Marines evolved a requirement for a twin-turbine troop/cargo assault helicopter to replace the piston engine types then in use. Following a design competition, Boeing/Vertol was selected to build its model 107M as the HRB-1, early in 1961. It retained the general configuration of its predecessors, including the aft sponsons carrying the fixed main gear, a fixed nose gear and built-in emergency flotation provisions so it could land and take off from the water in light seas. Special features included power-operated blade folding, integral cargo handling provisions, a rear loading ramp that could be left open in flight, personnel recovery and rescue equipment, and provisions for hoisting 10,000 pounds externally. These and other features marked a significant step forward in helicopter capability in the time period.

First flight in August 1962 was followed by a change in designation to CH-46A, development flight testing, (including the first NPE in January 1963), and BIS trials beginning in March 1964. Fleet introduction of CH-46As with the Marines and UH-46As with the Navy took place in November 1964. The latter were modified for use in the vertical replenishment role.

Production continued in subsequent years, along with modifications to improve some of the H-46's characteristics. With service in SEAsia came installation of guns and armor. Increased power requirements were met by installation of higher powered T-58-GE-10s in the CH/UH-46D models, which also featured new cambered (droop snoot) rotor blades. The final CH-46E, with further increased power, was preceded by the last production version, the CH-46F, before production was completed with delivery of the 524th H-46 in February 1971.

The early A models now serve as search and rescue HH-46As. CH-46s equip Marine Reserve squadrons, and conversion of earlier aircraft to the new CH-46E version was completed with fiberglass blades slated added to its other improvements. The current H-46 Sea Knight Block Upgrade provides for installation of increased fuel capacity stub wings and an emergency helicopter flotation system. The H-46 Dynamic Component Upgrade provides for safety, engineering and electronic improvements.