Arrius 2F Subject of FAA Airworthiness Directive

The FAA has issued an Airworthiness Directive for Turbomeca Arrius 2F turboshaft engines, citing insufficient clearance between the P3 air pipe and the rear right bulkhead. According to AD 2008-NE-43, investigations have shown that both the P3 air pipe and the rear right bulkhead were compliant with the original approved design. The Turbomeca engineering department concluded that the tolerance of assembly established during the design could result in some rubbing between parts. Friction between the pipe and the bulkhead might lead to premature wearing and eventual rupture of the P3 air pipe. The loss of P3 air pressure would then force the fuel control system to idle, which could have a detrimental effect in critical phases of flight. According to an FAA spokesman, the agency is issuing the AD to prevent an uncommanded power loss, which could result in an emergency autorotation landing or accident. The AD becomes effective August 19.