EASA AD CF-2021-15: Superseded by TCCA AD CF-2025-60

What to do

Operators of Bell Model 429 helicopters with serial numbers 57001 and above must perform initial inspections within specified flight hour or calendar time limits depending on aircraft usage and maintenance history. Inspections must be repeated every 400 flight hours or 12 months. Any defective rivets or excessive gaps must be repaired or replaced before further flight. Compliance must follow the procedures in Bell Alert Service Bulletin 429-19-47 Revision B.

Summary

The Canadian Airworthiness Directive CF-2021-15 addresses defective rivets at the junction of the tail rotor gearbox support and tailboom on Bell Helicopter Textron Canada Limited Model 429 helicopters, serial numbers 57001 and above. This directive mandates inspections and corrective actions to ensure structural integrity and prevent potential loss of helicopter control. It requires compliance with Bell's Alert Service Bulletin 429-19-47 Revision B dated January 27, 2021.

What changed

CF-2021-15 introduces mandatory initial and periodic general visual and detailed inspections of rivets at the tail rotor gearbox support and tailboom junction. It requires replacement or repair of any non-conforming rivets and correction of excessive gaps found during inspections. This directive enforces compliance with Bell's latest service bulletin to address a known quality issue with rivet installation.

Why it matters

This directive is critical for maintaining the structural integrity of the tail rotor assembly on Bell Model 429 helicopters, directly impacting flight safety. Operators and maintenance organizations must ensure timely inspections and repairs to prevent progressive structural degradation that could lead to loss of helicopter control. Compliance helps avoid in-service failures and regulatory penalties.

What to do

Summary

What changed

Why it matters

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