2009-25-10: Main gearbox
FAA order 2009-25-10 is an airworthiness directive in force since December 21, 2009. The FAA's subject line: Main gearbox. It names Sikorsky Aircraft Corp S-92: about 5 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Sikorsky Aircraft Corporation
- Models
- S-92A
- On this site
- Sikorsky Aircraft Corp S-92 5 registered
Dates and paperwork
- In force since
- December 21, 2009
- Published
- December 4, 2009 (signed November 25, 2009)
- Docket
- FAA-2009-1130
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The FAA's summary their words, unchanged
This amendment adopts a new airworthiness directive (AD) for the Sikorsky Model S-92A helicopters. This action requires a one-time visual inspection of the main gearbox (MGB) lube system filter assembly for oil filter damage. This action also requires if either the primary or secondary oil filter is damaged, replacing both filters, all packings, and the studs before further flight. This AD also requires replacing the oil filter bowl within 30 days after replacing a damaged filter and a daily leak inspection for an oil leak (no oil leaks allowed) during that 30-day interim period. This amendment is prompted by three reports of damaged oil filters or packings resulting from installing the filter assembly with an oversized packing possibly because of incorrect part numbers in the maintenance manual. Based on a previous accident investigation, failure of the oil filter bowl or mounting studs can result in sudden and complete loss of oil from the MGB. The actions specified in thisAD are intended to prevent complete loss of oil from the MGB, failure of the MGB, and subsequent loss of control of the helicopter.
The order itself the regulatory text, as published
Show the full text (4,344 characters)
Related safety bulletins advice on the same designs, not orders
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 30, 2026. Connections as data: /graph/directive/2009-25-10.json · aircraft systems.
