An Investigation of the Rotor Tip Path Height of the MH-60S Helicopter in View of Forklift Clearance in Support of the United States Navy Medium Lift Shipboard Logistics Mission

The purpose of this paper is to summarize Department of the Navy tests performed to measure rotor tip path height of the MH-60S helicopter and present an analysis of collected data to determine if safe cargo loading operations on the MH-60S can be conducted with a forklift while the rotor is engaged. Testing was conducted to measure the dynamic height of the rotor tip path plane during incremental cyclic displacements, rotor response to external disturbances, and pilot tendencies when centering the cyclic control stick. Additional information was gathered on representative forklifts in use on U.S. Navy ships, and shipboard operating procedures for cargo movement. A comparison between the forklift and rotor heights was conducted to evaluate the clearance available for forklifts transiting the rotor arc.

While it cannot be concluded that cargo loading using a forklift with the rotor engaged can be conducted without incident, substantial data were gathered that indicated that current safety precautions coupled with the clearance from the engaged rotor would allow for safe conduct of the evolution.

Specifically, if operations are conducted with low profile forklifts, which have an obstruction height shorter than the average male, rotor clearance is considered sufficient to preclude catastrophic interaction between the rotor and the equipment. Additional research, safety review, and equipment and publication changes are recommended to further increase the safety of conducting these operations.