The Boeing Vertol CH-46 Sea Knight is a medium-lift tandem rotor transport helicopter powered by twin turboshaft aircraft engines. It was used by the United States Marine Corps (USMC) to provide all-weather, day-or-night assault transport of combat troops, supplies and equipment. Additional tasks included combat support, search and rescue (SAR), support for forward refueling and rearming points, CASEVAC and Tactical Recovery of Aircraft and Personnel (TRAP). The Sea Knight was also the United States Navy’s standard medium-lift utility helicopter. Canada also operated the Sea Knight designated as CH-113. The commercial version is the BV 107-II, commonly referred to simply as the “Vertol”. It has a crew of five: two pilots, one crew chief, one aerial gunner/observer, one tail gunner and a capacity of 24 troops or 5,000 lb. It has a maximum speed of 166 mph, a range of 633 mi and a ferry range of 690 mi.