The CH-47 Chinook helicopter is the U.S. Army's only medium-lift helicopter. It is a twin-engine, tandem rotor, cargo helicopter.   Beginning in 1975, it was modernized to include new fiberglass rotor blades, transmission and drive systems, modularized hydraulics, electrical systems, advanced flight controls, triple hook cargo system, and an auxiliary power unit.

Credits - Imagery provided by the Defense Visual Information Center (DVIC)