EASA SIB 2008-70
FAA SAIB SW-08-37 - Sikorsky S-76 Helicopters - Inoperative Cyclic Control Stick Guard Override Mechanism
Summary
FAA Special Airworthiness Information Bulletin SW-08-37 addresses an issue with the inoperative cyclic control stick guard override mechanism on Sikorsky S-76 series helicopters, specifically those modified with Keystone Helicopter Corporation Supplemental Type Certificate SR01140NY-D. The bulletin highlights a safety concern where the stick guard's spring override mechanism may fail, potentially interfering with the forward movement of the cyclic stick during flight. EASA SIB No. 2008-70 supports the FAA's advisory and applies specifically to Sikorsky S-76C helicopters modified under the corresponding STC validated by EASA.
What Changed
This bulletin introduces awareness of a reported malfunction involving the cyclic control stick guard override mechanism on Sikorsky S-76 helicopters equipped with the Keystone STC. It recommends disabling the stick guard until a one-time functional check is performed, as detailed in Sikorsky Alert Service Bulletin 76-67-51 Revision A. The EASA SIB clarifies applicability to the S-76C model only, differing from the FAA's broader reference to the S-76 series.
Why It Matters
The inoperative override mechanism can cause interference with the cyclic stick's forward movement, which could affect helicopter control during critical phases of flight. Operators and maintenance personnel must be aware of this issue to prevent potential flight safety risks and ensure proper functionality of the stick guard. Compliance with the recommended functional check helps maintain operational safety and regulatory alignment.
What To Do
Operators of Sikorsky S-76C helicopters modified with Keystone STC SR01140NY-D should follow the Sikorsky Alert Service Bulletin 76-67-51 Revision A by disabling the stick guard until a one-time functional check is completed. Although not mandatory, it is strongly recommended to perform this action as soon as possible. For further information, contact the FAA Boston Aircraft Certification Office or EASA's Airworthiness Directives section.
AI-generated summary from official EASA source document. Always verify against the original.