In June 1964, CH-46A Sea Knight entered service with the US Marine Corps, framed in the HMM-265 Squadron. This variant had two T58-GE8-8B turboshaft engines of 1,250 shp each, which allowed it to carry up to 1,800 kg of cargo or 17 fully equipped soldiers, or 15 stretchers. In addition, it was also possible to carry external loads suspended from a cargo hook on the belly up to a maximum of 2,870 kg.The US Navy also commissioned 14 UH-46A Sea Knight, which were a slightly modified variant prepared for vertical replenishment missions. In this image we can see a UH-46A operating over the deck of the USS Parsons destroyer.In March 1966, CH-46 arrived at Vietnam War, and in little more than a year there were already more than 100 units supporting the American troops. These helicopters were fitted with armour plates to protect the engines and crew members. They were usually equipped with 12.7mm machine guns in the cockpit to provide defense during the dangerous takeoffs and landings in “hot zones”.During operations in Vietnam some accidents occurred due to the vibrations generated by the rear rotor, which weakened the structure and caused the fall to ground. This problem was solved and during the War the Sea Knight made more than 62,500 missions. In that period they carried 1,330,000 soldiers, 100,000 tons of cargo and evacuated more than 120,000 wounded, at the cost of 100 Sea Knight lost.Sea Knight had the ability to land and take off from the water which made it especially useful for rescue missions at sea. About 50 HH-46A were built, of which some were later transformed to the HH-46D variant with radar and special equipment for rescue. Some of them were converted to HH-46E variant that operated from the ground.The first CH-46A could carry only about 1,800 kg of cargo but the CH-46D, which appeared in 1966, increased its capacity to 3,200 kg or 25 equipped soldiers. This increase was due to the installation of the new T58-GE-10 turboshaft engines of 1,400 shp each. Despite this increase in power, the Marines usually used the Sea Knight for the transport of troops, leaving the supply task to the CH-53 Sea Stallion heavy helicopter.In 1966, the US Navy put in service ten UH-46D, (as the one on the image), similar to the Marines’s CH-46D. They were used mostly to carry supplies to ships on the high seas, although they could also perform rescue tasks if was necessary. The Navy withdrew all UH-46s in 2004, when they were replaced by MH-60S Seahawk helicopters.From 1968 to 1971, 174 CH-46F were built, they had the same powerplant as D variant, but with modern avionics. The Sea Knight had an internal winch that could be used to assist the introduction of loads in the cargo bay. The Marines affectionately nicknamed as “Phrog”, and for almost 5 decades it has been deployed with them in all their missions.CH-46 served with 17 US Marine Corps assault Squadrons plus another training Squadron. These Squadrons were the HMM-161/163/164/166 and 268 along with the HMT-301 training unit based in Tustin, California. The HMM-162/204/261/263/264/266 and 365 based in New River, North Carolina, the HMM-165/265 and 364 based in Kaneohe Bay, Hawaii, the HMM-774 based in Norfolk, Virginia, and the HMM-764 based in El Toro, California.CH-46 Sea Knight have participated in major operations carried out by the Marines such as the Vietnam War, Operation Urgent Fury on the Island of Grenada in 1983, or the Invasion of Iraq in 2003. In this last mission, the passage of time began to note in the kindly Sea Knight, which suffered from breakdowns and difficult maintenance. Soon after in 2006, with the arrival of the new MV-22 Osprey tiltrotor aircraft, Sea Knights began to be phased out. This image shows an amphibious assault maneuver along with South Korean Marines’s vehicles.The CH-46 was used mainly by the United States, although some units were exported to Sweden, (ten units designated as HKP-4A), Canada, (six CH-113 Labrador for the Air Force plus twelve CH-113A Voyageur for the Army) and Japan, where Kawasaki built it under license with the designation KV-107. This image shows a Canadian Air Force’s CH-113 Labrador, model that was used in rescue missions.
