On September 26, 1995, a Bell 47G-3B1 (registration N92HA) operated by Ward Aviation, Inc. was involved in an aviation accident near Union Church, MS. Investigators recorded the probable cause as: The rod end bearing was found to not contain a significant amount of grease and was excessively worn which allowed the monoball to separate from the housing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Shortly after takeoff, a helicopter lost cyclic control. During forced landing, engine power reduction led to pitch-up and left roll, causing main rotor blade ground contact. Postcrash examination revealed a separated rod end bearing at the main rotor head, which was found excessively worn and lacking grease.
Introduction
Shortly after takeoff, the pilot of a helicopter lost cyclic control. During the subsequent forced landing, when engine power was reduced, the helicopter pitched up and rolled to the left. The main rotor blades then contacted the ground.
Sequence of Events
The loss of cyclic control occurred shortly after takeoff. As the pilot attempted a forced landing, the reduction in engine power resulted in the helicopter pitching up and rolling left. This attitude change caused the main rotor blades to strike the ground.
Postcrash Examination
A postcrash examination revealed that a rod end bearing on the main rotor head had separated. This bearing connects the stabilizer bar to the damper. The rod end bearing was found to lack a significant amount of grease and was excessively worn. This wear allowed the monoball to separate from the housing.
Probable cause
The rod end bearing was found to not contain a significant amount of grease and was excessively worn which allowed the monoball to separate from the housing.