[2] Following award of an Army contract for an HLH prototype in 1973, Boeing did move forward on building an oversized flying crane machine, the "XCH-62".

[5]: 3 Failures in the spiral bevel gearing of the main transmission were experienced in tests because the method of analysis employed had not considered the effect of rim bending.

The U.S. Army's XCH-62 HLH aft rotor transmission was finally successfully tested at full design torque and speed, but the US Congress cut funding for the program in August 1975.

[10] In the mid-1980s, the Army, the US National Aeronautics & Space Administration (NASA), and the Defense Advanced Research Projects Agency (DARPA) collaborated on a scheme to finish the XCH-62 for experimental flights, requesting a combined US$71 million in funding through fiscal year 1989.

[1] The prototype was moved from a warehouse storage site in Philadelphia, Pennsylvania, floated by barge to Panama City, Florida,[12] and then lifted by a CH-47D Chinook helicopter to the US Army Aviation Museum at Fort Rucker, Alabama on December 8, 1987.

[15] Its widely spaced landing gear would allow it to straddle heavy cargoes such as armored vehicles, and still carry twelve troops in its slender fuselage.

[15] Data from America's heavy lift helicopter[18]General characteristics Performance Related development Aircraft of comparable role, configuration, and era