EASA AD US-2017-26-03
Main Rotor - Rod End Bearing Assemblies - Inspection
Summary
Federal Register Volume 82, Number 243 (December 20, 2017) - Airworthiness Directive 2017-26-03 is a final rule issued by the FAA addressing Enstrom Helicopter Corporation models F-28, F-28A, F-28C, F-28C-2, F-28C-2R, F-28F, F-28F-R, TH-28, 280, 280C, 280F, 280FX, 480, and 480B. This directive mandates inspection of specific main rotor rod end bearing assemblies to detect corrosion and prevent potential failure that could lead to loss of a main rotor blade. The directive was prompted by an accident involving an Enstrom Model 480B helicopter.
What Changed
This new airworthiness directive requires a one-time inspection within 5 hours time-in-service of certain rod end bearing assemblies for corrosion using a magnifying glass. If corrosion is found, the bearing assembly must be replaced before further flight. Additionally, inspection results must be reported to the FAA within 10 days. This AD expands the scope beyond the previously identified part numbers to include all similarly designed bearing assemblies due to lack of evidence limiting the issue to a specific batch.
Why It Matters
This directive is critical for aviation professionals as it addresses a safety risk that could result in catastrophic failure of the main rotor blade, leading to loss of control of the helicopter. Operators and maintenance organizations must ensure timely inspections and replacements to maintain airworthiness and comply with FAA regulations. Compliance teams need to manage reporting requirements and prepare for potential future rulemaking based on inspection outcomes.
What To Do
Operators of affected Enstrom helicopter models must perform a one-time inspection of the specified rod end bearing assemblies for corrosion within 5 hours time-in-service after January 4, 2018. If corrosion is detected, the bearing assembly must be replaced before further flight. Inspection findings must be reported to the FAA's Chicago ACO Branch within 10 days of inspection completion. Stakeholders should monitor for any subsequent FAA rulemaking that may introduce additional inspection intervals or requirements.
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