Airworthiness Directive · Amendment 39-18555 · Turbomeca S.A. Turboshaft Engines
Turbomeca S.A. Turboshaft Engines
This AD applies to Turbomeca S.A. MAKILA 2A and MAKILA 2A1 turboshaft engine models with a high-pressure gas generator module (M03) that has modification (mod) TU 52 installed.
We are adopting a new airworthiness directive (AD) for all Turbomeca S.A. MAKILA 2A and MAKILA 2A1 turboshaft engines. This AD requires repetitive diffuser inspections and replacement of those diffusers that fail inspection. This AD was prompted by two occurrences of crack initiation on a ferrule of the diffuser. We are issuing this AD to prevent rupture of the ferrule of the diffuser, which could result in engine fire and damage to the helicopter.
(1) Borescope inspect the centrifugal diffuser ferrule, part number 0298210100, prior to the ferrule accumulating 700 hours, time since new or time since replacement or within 30 hours from the effective date of this AD, whichever is later. Use Accomplishment Instructions, paragraphs 2.4.1 through 2.4.2.2.1, of Turbomeca S.A. Alert Mandatory Service Bulletin (MSB) No. 298 72 2832, Version C, dated April 15, 2016, to do the borescope inspections required by this AD.
(2) Repeat the borescope inspection required by this AD every 300 hours since last inspection.
(3) If any crack, loss of contact between the ferrule and diffuser axial vane, or any contact between the injection manifold supply pipe and the diffuser ferrule is found, remove the diffuser case and replace the ferrule with a part eligible for installation.
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.
