AD FAA-2010-0904

We are adopting a new airworthiness directive (AD) for Turbomeca Arriel 1B turboshaft engines. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as an increase in hot gas ingestion and an increase of temperature in the gas generator (GG) turbine rotor, potentially resulting in turbine damage and an uncommanded in-flight shutdown. We are issuing this AD to prevent over-temperature damage of the GG turbine, which could result in an uncommanded in-flight engine shutdown, and a subsequent forced autorotation landing or accident.