The FAA is proposing an airworthiness directive that would require inspections of main rotor servo-controls on approximately 980 Airbus helicopters registered in the United States, covering multiple variants of the AS350, AS355, and EC130 families.
The unsafe condition centers on a lock washer that can lose its clamping ability when paint or protective coating is present on its surface. Loss of torque retention could allow the upper ball bearing end to separate from the main rotor servo-control — a failure the FAA says could result in loss of helicopter control.
Affected models include the AS350B3/H125 and the EC130/H130, platforms widely used in firefighting, law enforcement, EMS, and sightseeing operations. Airbus issued service bulletins addressing the issue in April. European regulators made inspections mandatory in July before the FAA published its proposal this week.
The proposed AD would require inspection of all three main rotor servo-controls. If components are removed and reinstalled during that process, follow-on checks are also required. Depending on findings, corrective action ranges from cleaning the affected threads to replacing entire servo-control assemblies. The FAA puts the base inspection and reporting cost at $360 per helicopter. A full servo-control replacement can run as high as $54,640. The agency has not yet estimated how many aircraft may need replacement parts.
This proposal extends scrutiny that began earlier in 2025, when the FAA ordered inspections on Airbus Dauphin and EC155 helicopters after two reports of lost tightening torque, including one confirmed separation. Investigations on those models identified paint on a lock washer as the root cause, and European regulators subsequently expanded requirements to additional Airbus types. The current proposal is the result of that expansion reaching the AStar and TwinStar families.
Both the FAA and the European Union Aviation Safety Agency treat the inspection requirements as interim measures. Airbus is working on a design change intended to eliminate the coating problem at the source. The FAA is accepting public comments on the proposed AD through December 3.
