EASA AD US-2024-07-01
Propellers - Auxiliary Motor and Pump - Replacement
Summary
The Federal Aviation Administration's Airworthiness Directive 2024-07-01 addresses Hamilton Sundstrand Corporation Model 14SF-7, 14SF-15, and 14SF-23 propellers installed on aircraft including De Havilland Aircraft of Canada Limited DHC-8 series. This directive mandates the replacement of a specific auxiliary motor and pump to prevent in-flight failure to feather the propeller. It also prohibits the installation of the affected auxiliary motor and pump part number on these propellers.
What Changed
This new airworthiness directive requires removal and replacement of auxiliary motor and pump part number 782655-3 with part number 782655-4 on the specified Hamilton Sundstrand propellers. It introduces a prohibition on installing the older part number on any of the affected propellers. The directive clarifies that the installation prohibition applies only to the propellers listed in the applicability section.
Why It Matters
This directive is critical for aviation professionals because failure of the auxiliary motor and pump to feather the propeller can lead to reduced aircraft controllability and potential loss of control. Operators and maintenance organizations must ensure compliance to maintain airworthiness and safety. The directive prevents installation of faulty parts, reducing risk of in-flight emergencies related to propeller feathering systems.
What To Do
Operators must remove and replace the auxiliary motor and pump part number 782655-3 with part number 782655-4 within 30 months of June 3, 2024. After replacement, a post-installation system test must be performed following the specified service bulletin instructions. Installation of the older part number on the affected propellers is prohibited after the effective date.