Rotorcraft Flight Control - Main Rotor (M/R) Servo Pushrod Assembly - Inspection
- Published
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- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of affected Sikorsky S-76 models must inspect the main rotor servo pushrod assemblies within 300 hours time-in-service. They must check for lockwire passage, jamnut security, apply specified torque if needed, and mark the assemblies with slippage marks. Any pushrod assembly failing inspection must be replaced before further flight. Compliance is mandatory by January 2, 2018.
Summary
Federal Register Volume 82, Number 227, Airworthiness Directive 2017-19-01 is a final rule issued by the FAA addressing Sikorsky Aircraft Corporation Model S-76A, S-76B, S-76C, and S-76D helicopters. It mandates inspection and marking of the main rotor servo pushrod assemblies with specific part numbers to prevent failure. The directive aims to enhance flight safety by addressing a critical component failure risk.
What changed
This new airworthiness directive introduces mandatory inspections of the main rotor servo pushrod assemblies and requires applying slippage marks to detect and prevent loose jamnuts. It specifies inspection procedures, torque application, and replacement criteria for affected pushrod assemblies. The AD also clarifies that removed parts do not need to be returned to Sikorsky, differing from the related service bulletin.
Why it matters
This AD is crucial for aviation professionals as it addresses a safety risk that could lead to loss of main rotor flight control and potential helicopter accidents. Operators and maintenance teams must ensure compliance to maintain airworthiness and prevent in-flight failures. The directive provides clear inspection and maintenance requirements to mitigate this unsafe condition effectively.
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