EASA AD 2025-0267-E
Engine — Propeller Gearbox — Inspection
Summary
EASA Airworthiness Directive 2025-0267-E is an emergency directive addressing the inspection of propeller gearboxes on BRP-Rotax 915 i and 916 i series engines installed on various general aviation aeroplanes and powered sailplanes. The directive targets specific gearbox part numbers and serial numbers to ensure the presence of a critical collar nut. It applies to engines installed on EASA CS-23, CS-LSA, CS-VLA, or CS-22 certified aircraft.
What Changed
This new emergency airworthiness directive introduces a mandatory inspection of the propeller gearbox to verify the installation of the M40 x 1.5 collar nut, which was found missing on a recently manufactured engine. It requires corrective actions if the collar nut is missing and prohibits installation of suspect gearboxes from the effective date. The directive also allows replacement of affected gearboxes with serviceable ones as an alternative compliance method.
Why It Matters
This directive is critical for aviation professionals because the missing collar nut can lead to propeller shaft detachment during operation, potentially causing in-flight engine failure or loss of control. Operators and maintenance organizations must ensure compliance to prevent safety risks and maintain airworthiness. Compliance teams need to track affected engines and gearboxes to avoid installation of suspect parts and ensure timely inspections.
What To Do
Operators of Group 1 engines must inspect the propeller gearbox before the next flight after 2 December 2025, following the instructions in BRP-Rotax Alert Service Bulletin ASB-915 i-021 / ASB-916 i-009 Revision 1. If the collar nut is missing, corrective actions must be completed before further flight. Installation of suspect gearboxes is prohibited from the effective date, and replacing affected gearboxes with serviceable ones is an acceptable alternative.