Airworthiness Directive · Amendment 39-16892 · Turbomeca Arriel 1 Series Turboshaft Engines
Turbomeca Arriel 1 Series Turboshaft Engines
This AD applies to Turbomeca Arriel 1A, 1A1, 1B, 1C, 1C1, 1C2, 1D, 1D1, and 1S1 turboshaft engines that have incorporated Modification TU347.
We are revising an existing airworthiness directive (AD) for the products listed above. This AD was prompted by Turbomeca restoring all or part of the life limits of the affected discs, and European Aviation Safety Agency's (EASA) issuance of AD 2010-0101R2, dated March 24, 2011, to do the same. Turbomeca has introduced a reinforced eddy- current inspection (ECI) which, combined with a revised analysis, allows the life limit of the affected discs to be extended. We are issuing this revision to prevent failure of the gas generator (GG) second stage turbine disc which could result in the release of high energy debris and damage to the helicopter.
(1) Comply with this AD within the compliance times specified, unless already done.
(2) Remove from service the GG second stage turbine discs, part number (P/N) 0 292 25 040 0, that do not have the “CFR” marking before exceeding 4,000 cycles-in-service (CIS) since-new.
(3) Remove from service gas generator second stage turbine discs, P/N 0 292 25 040 0, that have the “CFR” marking before exceeding 6,500 CIS since-new.
(1) After the effective date of this AD, do not install into any engine gas generator second stage turbine discs, P/N 0 292 25 040 0, that do not have the “CFR” marking and have 4,000 or more CIS since-new.
(2) After the effective date of this AD, do not install into any engine gas generator second stage turbine discs, P/N 0 292 25 040 0, that have the “CFR” marking and have 6,500 or more CIS since-new.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
