AD NUMBER: 2009-12-51

MANUFACTURER: Turbomeca S.A. Arriel 1A1, 1A2, 1B, 1C, 1C1, 1C2, 1D, 1D1, 1E2, 1K1, 1S, and 1S1 turboshaft engine
SUBJECT: Airworthiness Directive 2009-12-51

SUMMARY: This emergency AD results from reports of oil leaks from certain reduction gearbox (module M05) front casings. The engine manufacturer reported that the lubrication duct plug was not properly bonded/ glued in place. This condition, if not corrected, could result in loss of the lubrication duct plug, followed by a rapid draining of the oil tank, without indication to the cockpit through low oil pressure warning. This condition can lead to uncommanded in-flight engine shutdown, possible engine fire, and an emergency autorotation landing.

Explanation of Relevant Service Information

We have reviewed Turbomeca S.A. Mandatory Service Bulletin (MSB) No. A292 72 0825, Version A, dated May 27, 2009. The MSB identifies the affected modules M05 by serial number, and describes procedures for initial and repetitive visual inspections for oil leaks, and repair of affected modules M05.

FAA’s Determination and Requirements of the Rule

We have identified an unsafe condition that is likely to exist or develop on other Turbomeca S.A. Arriel turboshaft engines of this same type design. This AD requires initial and repetitive visual inspections of affected modules M05 for oil leakage, repair if leaking, and repair of all affected modules as terminating action to the repetitive inspections. You must use the service information described previously to perform these actions.

FMI: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/281F3E0B2293F239862575CB00720F97?OpenDocument