Vertical MRO Alerts: By Bell - Ep 9: Bell 429 Main Rotor Mast Inspection

Welcome to Vertical MRO Alerts, presented by Bell! In this Alert, Bell 429 Product Support Engineering Lead Sebastien Rousseau discusses Alert Service Bulletin 429-26-74, which introduces a one-time inspection of certain Bell 429 main rotor mast assemblies for machining marks on the inner diameter. Sebastien explains Bell's investigation that these machining marks can affect mast fatigue life, and the required actions based on the mast's accumulated hours. He also reviews the compliance timelines, inspection requirements, and the latest updates included in Revision A, including mandatory borescope use and a simplified inspection procedure that reduces the maintenance required to accomplish the bulletin. Maintainers who have questions or are uncertain about their inspection findings are encouraged to contact Bell Product Support for assistance. For full details and compliance requirements, operators should always refer directly to Alert Service Bulletin 429-26-74. The full library of episodes is available to listen to on demand. We want to hear from you! – techtalk@bellflight.com Need help with your Bell helicopter? – productsupport@bellflight.com