Pratt & Whitney JT8D Series Turbine Engine Accessory Drive
- Published
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators and maintenance facilities should install the redesigned aluminum bushing during the next engine or module maintenance visit, regardless of the scheduled maintenance or reason for engine removal. This installation should follow Pratt & Whitney Alert Service Bulletin A6495 dated December 17, 2009. No mandatory compliance deadline is specified, but timely action is recommended to mitigate risk.
Summary
The Special Airworthiness Information Bulletin SAIB: NE-10-32 is an FAA informational bulletin addressing potential accessory gearbox bevel gear fractures in all Pratt & Whitney JT8D series turbine engines. It highlights issues caused by forward movement of the constant speed drive (CSD) bearing bushing that can lead to gear misalignment and fractures. The bulletin is intended for owners, operators, and certificated repair facilities operating JT8D engines.
What changed
This bulletin introduces a redesigned aluminum repair bushing for the gearbox rear housing assembly to improve axial load retention and prevent forward movement of the CSD steel bushing. The new design increases retention by 13 times compared to the previous bushing and reduces the risk of bevel gear fractures. Pratt & Whitney recommends installing this redesigned bushing as per Alert Service Bulletin A6495.
Why it matters
This information is important for aviation professionals because fractured bevel gears have caused in-flight shutdowns and nacelle uncontainment events, which, although not resulting in aircraft damage, pose operational risks. Implementing the redesigned bushing reduces the likelihood of these events, enhancing engine reliability and safety. Maintenance and compliance teams need to be aware to prevent potential unscheduled engine removals and operational disruptions.
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