Compared to the CH-46 Sea Knight: Continuous bulge along lower sides of fuselage; engines exposed below rear rotor; five round portholes, fixed four-wheel landing gear. Much rarer civilian versions show more than a dozen rectangular passenger windows on each side.

The workhorse Army troop carrier of the Vietnam War, the Chinook was also used as a heavy cargo transport. More than 400 older Chinooks are being converted to the 47D standard, which almost doubles the useful load and range of the Vietnam-era copters. Civilian versions are in service in the Far East, at both Gulf of Mexico and North Sea ports as airbuses for platform workers, and in the Pacific Northwest as airborne "fire engines."