AD FAA-2025-3996

The FAA is superseding Airworthiness Directive (AD) 2025-06- 51, which applied to certain Bell Textron Canada Limited (Bell) Model 505 helicopters. AD 2025-06-51 required removing all ballast weights from the aft movable ballast box assembly and prohibited the use of ballast weights within the aft movable ballast box assembly. Since the FAA issued AD 2025-06-51, Bell has developed a modification to the ballast box door assembly and the FAA has determined that the new actions would terminate the requirements of AD 2025-06-51. This AD requires installing the modification to the aft movable ballast box door assembly. The FAA is issuing this AD to address the unsafe condition on these products.