[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.

[1] One danger that its crews had to maintain awareness of was the strong downwash generated by the rotors; nearby tents were particularly at risk of being blown away.

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.