EASA SIB SAIB-2024-05
Engine / Transmission Coupling, Gearmotor Assembly
Summary
The FAA Special Airworthiness Information Bulletin SAIB: 2024-05 is an informational bulletin addressing a potential airworthiness concern involving the gearmotor assembly, part numbers D276-1 and D276-3, on belt-tension actuators of Robinson Helicopter Company Model R44 and R44 II helicopters. This bulletin also applies to belt-tension actuator assemblies C051-1 and C051-2, Revision AC and prior, sold as spares containing these gearmotors. The bulletin informs operators and maintenance personnel about the issue but does not mandate regulatory action.
What Changed
SAIB: 2024-05 introduces awareness of potential loosening of specific gearmotor assemblies on RHC R44-series helicopters due to manufacturing issues with screws and missing thread locking adhesive. It highlights updates made by Robinson Helicopter Company to the maintenance manual and the issuance of Service Bulletin SB-115, which requires inspection and torque stripe verification of the gearmotor assembly. This bulletin does not impose mandatory requirements but recommends inspection procedures.
Why It Matters
This information is important for aviation professionals because loose gearmotor assemblies could affect the reliability of belt-tension actuators on RHC R44 helicopters, potentially impacting safe operation. Maintenance and inspection teams need to be aware of the updated inspection procedures to detect and prevent gearmotor loosening. Compliance teams should note that while no airworthiness directive is issued, following the recommendations helps maintain aircraft safety and regulatory compliance.
What To Do
Operators and maintenance personnel should inspect the gearmotor assemblies for looseness, replace any defective units, and apply torque stripes as specified in Robinson Helicopter Company Service Bulletin SB-115. Additionally, at every 100-hour or annual inspection, the gearmotor torque stripe verification procedure in the updated R44 maintenance manual should be followed. These actions are recommended to ensure ongoing airworthiness and safety.