Federal Register #2026-07218

FAA Proposed Airworthiness Directive for Columbia Helicopters Model 234 and CH-47D Helicopters – Corrosion Inspection and Remediation

The Federal Aviation Administration (FAA), under the Department of Transportation, is proposing a new airworthiness directive (AD) targeting Columbia Helicopters, Inc. Model 234 and all Restricted Category Model CH-47D helicopters due to corrosion issues on flight control rigid connecting links. - Government Buyer: - Department of Transportation, Federal Aviation Administration (FAA), West Certification Branch - OEMs and Vendors Mentioned: - Columbia Helicopters, Inc. (primary OEM) - Billings Flying Service, Inc. - Tandem Rotor, LLC - Unical Air Inc. - Products/Services Requested: - Inspection, repair, or replacement of flight control rigid connecting links with part numbers: 145C33401, 145C33402, 145C33407, 145C33408, 145C33409, 145C334010, 145C334011, 145C334012 - Total affected: 324 connecting links across 36 helicopters - Repetitive borescope inspections for corrosion - Reporting of inspection results to the FAA for four inspection cycles - Unique or Notable Requirements: - Prohibits installation of certain connecting links unless specific requirements are met - Inspections must be performed at intervals of 12, 18, or 24 months depending on corrosion severity - Immediate action required within 30 days of AD effective date - Focused on preventing unsafe conditions that could compromise helicopter controllability and flight safety - Locations: - FAA West Certification Branch, 3960 Paramount Boulevard, Lakewood, CA - FAA, 10101 Hillwood Parkway, Fort Worth, TX - U.S. Department of Transportation, Docket Operations, 1200 New Jersey Avenue SE, Washington, DC - U.S. Army Aviation and Missile Command (AMCOM), Redstone Arsenal, AL

Description

The FAA proposes a new airworthiness directive (AD) for Columbia Helicopters, Inc. Model 234 helicopters and Restricted Category Model CH-47D helicopters due to corrosion detected on certain flight control rigid connecting links. The AD would require repetitive borescope inspections, repair or replacement of corroded parts, and reporting of inspection results to the FAA. The directive aims to address unsafe conditions that could lead to reduced controllability of the helicopter and ensure flight safety.

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