Federal Register #FAA20267220

FAA Proposed Airworthiness Directive for Bell 407 Helicopter Tail Boom Safety

This opportunity concerns a proposed airworthiness directive (AD) from the Federal Aviation Administration (FAA) for Bell Textron Canada Limited Model 407 helicopters. - Government Buyer: - Federal Aviation Administration (FAA), Aircraft Certification Service, International Validation Branch - OEM Highlight: - Bell Textron Canada Limited is the primary OEM referenced - Other Regulatory Bodies: - Transport Canada - European Union Aviation Safety Agency (EASA) - Products/Services Requested: - Repetitive inspections of the tail boom attachment structure for cracks, dents, loose fasteners, deformation, corrosion, and general condition - Torque inspections and replacement of tail boom attachment hardware (bolts, nuts, and related hardware) - Detailed inspection of the tail boom assembly and aft fuselage structure, including upper and lower longerons, bulkheads, and intercostals - Revision of the airworthiness limitations section (ALS) in the maintenance manual to include new life limits for tail boom attachment bolts - Prohibition of installation of upper-left longeron assemblies with part numbers 206031314237B and 206031314237S - Unique/Notable Requirements: - The directive is based on Transport Canada AD CF202559 and EASA AD 20240136 - The main objective is to address the unsafe condition caused by broken upper-left tail boom attachment bolts, which could result in tail boom separation and loss of helicopter control - No specific procurement of products or set quantities; the focus is on compliance with maintenance and inspection actions - The opportunity is for maintenance compliance, not for the purchase of new hardware, except as required for replacement during inspections

Description

The FAA proposes to supersede Airworthiness Directive (AD) 2022-27-08 for certain Bell Textron Canada Limited Model 407 helicopters. The proposed AD requires repetitive inspections of the tail boom attachment structure, torque inspections, replacement of attachment hardware, and detailed inspections of the tail boom assembly and associated aft fuselage structure as a terminating action. It also prohibits installing certain longeron assemblies and requires revising the airworthiness limitations section of the helicopter maintenance manual to include a new life limit for the tail boom attachment bolts. The AD addresses an unsafe condition involving broken upper-left tail boom attachment bolts that could lead to separation of the tail boom and loss of control of the helicopter.

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