[1] The company was already working on the Sikorsky S-64 Skycrane, a civil-orientated heavy lift rotorcraft that was designed specifically for the purpose of carrying large payloads externally; the development of a military-configured derivative was viewed as a natural option.

[1] One innovative feature for any helicopter of the era was the incorporation of an automatic flight control system, effectively a fly-by-wire arrangement.

It was most prolifically used during the Vietnam War, typically to provide logistical support and heavy transport activities in aid of American ground troops.

In the theater, CH-54s would routinely be used to reposition artillery pieces such as the M101 howitzer, and even airlift bulky payloads such as bulldozers and patrol boats.

[12][13] One unusual use of the type came under the Combat Trap programme, which saw it drop 10,000 lb bombs, intended for clearing landing zones.

[14] As a heavy transport helicopter, capable of retrieving numerous types of downed aircraft, it proved to be highly successful.

Due to budget cuts, the Heavy Lift Helicopter (HLH) program was canceled and the CH-54 was not upgraded with larger engines.

The relatively small fleet proved costly to maintain, thus the tandem-rotor Boeing CH-47 Chinook, a rival heavy lift helicopter, gradually supplemented the CH-54 for most transport duties, eventually replacing it in Regular Army aviation units during the 1980s.

Unusual payloads include whole antenna towers and log cabins; another example was the use of a CH-54 to airlift air conditioners onto the roof of the Pentagon.