Summary
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (Bell) Model 427 helicopters. This AD was prompted by a report of a cracked transmission oil check valve (check valve). This AD requires inspecting and measuring certain check valves and, depending on the results, repetitively inspecting and removing the check valve from service if it has leaks or is cracked. This AD also prohibits installing the affected check valves on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
Directive Details
AD Number
FAA-2025-1727
Document Number
2025-22623
Type
Rule
Publication Date
December 12, 2025
Effective Date
January 16, 2026
Affected Manufacturer
Bell Textron Canada Limited
Criticality
routine
Emergency
No
Docket ID
Docket No. FAA-2025-1727
Topics
Official Documents
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