The Boeing CH-46 Sea Knight is a medium-lift tandem rotor cargo helicopter used by the United States Marine Corps for all-weather, day-or-night assault transport of combat troops, supplies, and equipment, with assault support as its primary function and supply and equipment movement as a secondary role. Its additional tasks include combat support, search and rescue, support for forward refueling and rearming points, medivac, and Tactical Recovery of Aircraft and Personnel. The example built in 1967 underwent continuous upgrades and modifications during its service life and served in every major conflict involving the United States Marine Corps until it was damaged after a hard landing in Iraq in June 2004. During service in Vietnam, it took part in a rescue mission on January 30, 1970, during which crew chief PFC Raymond “Mike” Clausen performed heroic deeds that led to his award of the Congressional Medal of Honor. This helicopter type was built in more than 600 examples by Boeing Vertol Corporation and had a crew of four, carrying up to 25 troops.