Airworthiness Directive · Amendment 39-11652 · Turbomeca Makila 1 Series Turboshaft Engines
Turbomeca Makila 1 Series Turboshaft Engines
Turbomeca Makila 1A and 1A1 turboshaft engines, installed on but not limited to Aerospatiale AS 332 Super Puma, AS 532 Cougar, and SA 330 Puma helicopters.
Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD), applicable to Turbomeca Makila 1 series turboshaft engines, that requires a one-time visual inspection of the scavenge and lubrication systems for obstruction due to coke deposits, then reconditioning of the engine oil system prior to return to service. This amendment is prompted by a report of an in-flight engine shutdown due to roller bearings contaminated by certain types of detergent oil. The actions specified by the proposed AD are intended to prevent in-flight engine shutdown due to roller bearing failure following oil contamination.
To prevent in-flight engine shutdown due to roller bearing failure following oil contamination, accomplish the following:
(a) Within 25 hours time-in-service (TIS) after the effective date of this AD, accomplish the following:
(1) For engines that have been operated with 7.5 centistoke (cSt) oil for more than 100 hours TIS, and for engines whose operators can not show documentation that the engine has been operated with 7.5 cSt oil for 100 hours or less TIS, accomplish the following:
(i) Perform a one-time visual inspection of the scavenge and lubrication systems for obstruction due to coke deposits and repair as required, in accordance with section 2.A. and 2.B. of the ‘Instructions for incorporation’ section of Turbomeca Makila 1 Service Bulletin (SB) No. A298 71 0137, dated December 22, 1997.
(ii) Replace the oil with approved oil other than 7.5 cSt and then recondition and check the engine oil system in accordance with section 2.C. and 2.D.(1) Of Turbomeca Makila 1 SB No. A298 71 0137, dated December 22, 1997, prior to return to service.
(2) For engines that have been operated with 7.5 cSt oil for 100 hours or less TIS, replace the oil with approved oil other than 7.5 cSt and then recondition the engine oil system prior to return to service, in accordance with section 1.A.(2)(b) of Turbomeca Makila 1 SB No. A298 71 0137, dated December 22, 1997.
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.
