AD Issued for AStar/TwinStar Helicopters - National Agricultural Aviation Association

The FAA has issued a new airworthiness directive (AD) for Airbus AS350 (AStar) and AS355 (TwinStar) Helicopters. This AD was prompted by a manufacturer assessment that determined additional actions are necessary to improve particle detection for main gearboxes (MGBs) with certain planet gear bearings installed. This AD requires repetitively inspecting the MGB bevel wheel for the presence of particles, repetitively inspecting the MGB magnetic plug for particles, and prohibits installing an affected MGB unless certain requirements are met. These actions are specified in European Union Aviation Safety Agency (EASA) AD 2023-0044.

AD 2025-06-04 (this AD) is effective May 9, 2025.