Differences in reliability and maintainability data were examined on two groups of USAF H-3 helicopters with distinctly different vibration characteristics. One H-3 helicopter group was equipped with the rotor-mounted vibration adsorber, a device which reduces helicopter vibration induced by the rotor, and a second aircraft group did not have the absorber. The aircraft were alike in all other respects. The analyses performed on these data show a significant reduction in the failure rate and direct maintenance for the H-3 helicopters with absorbers and with reduced vibration levels. Correspondingly, life-cycle costs show a significant reduction of approximately 10% for the overall aircraft. At the subsystem and component levels, the same reductions are shown in almost every case with the exception of certain navigation and avionics components.