The Boeing CH-47 Chinook is a tandem-rotor helicopter originally developed by American rotorcraft company Vertol and now manufactured by Boeing Defense, Space & Security. The Chinook is a heavy-lift helicopter that is among the heaviest lifting Western helicopters. Its name, Chinook, is from the Native American Chinook people of Oregon and Washington state.

Piasecki Helicopter Corporation designed and manufactured helicopters in Philadelphia and nearby Morton, Pennsylvania, in the late 1940s and the 1950s. Its founder, Frank Piasecki, was ousted in 1956 and started a new company, Piasecki Aircraft. Piasecki Helicopter was renamed Vertol Corporation in early 1956. Vertol was acquired by Boeing in 1960 and renamed Boeing Vertol.