The Hughes OH-6 Cayuse (nicknamed Loach, after the requirement acronym LOH—Light Observation Helicopter) is a single-engine light helicopter with a four-bladed main rotor used for personnel transport, escort and attack missions, and observation. The helicopter derives its name from the Cayuse people. Hughes Helicopters also developed the Model 369 as a civilian helicopter, and the Hughes Model 500, currently produced by MD Helicopters as the MD 500.