After winning the U.S. Army's 1952 competition for a light utility helicopter, the H-1 "Huey" became the West's most popular, most versatile, and longest-lived military helicopter. In 1962, the U.S. Marine Corps selected the turbine-powered H-1 to replace their piston-engine H-34s, and shortly afterward the Navy also began acquiring H-1s, including the TH-1L version for intermediate helicopter training. Over the following decades, the Marines and Navy operated several utility and attack versions of the Huey. Although Navy H-1s, including TH-1Ls, were retired in 1983, the H-1 remains in Marine Corps service as the UH-1Y Venom and AH-1Z Viper. Bureau Number 157842 was accepted by the Navy in April 1970 and served with the Navy's Air Training Command until August 1983, when it was retired and transferred to the Naval Air Test Center's Rotary Wing Aircraft Test Directorate. As a ground test article, it was fitted with instrumentation to measure the unique vibration signatures of various intentionally induced gearbox faults, and findings from this research helped develop a means for detecting gearbox problems before failure.