Document ID: chunk:federal_register_of_legislation:F2009L01698:body:0:p1
Version: federal_register_of_legislation:F2009L01698
Segment Type: other
Provision Reference: 
Character Range: 0–2946

AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Turbomeca Turbine Engines - Makila Series
AD/MAKILA/14  Engine Control Unit - Comparator/Selector Boards  7/2009 DM

Applicability:  Makila 1A and 1A1 turboshaft engines, all serial numbers, having Engine Control Units (ECU) equipped with TU250 Comparator / Selector (CS) boards with serial numbers (S/N) in the range 241 EL to 1192 EL.
                Note 1:  CS boards with S/N in the above range are hereafter referred to as the suspect batch.
                Note 2:  Makila 1A and 1A1 engines are installed in, but not limited to, Eurocopter AS 332 C, C1, L and L1 helicopters.
Requirement:       1. If both TU250 CS boards on the same helicopter are from the suspect batch and if both have an operating time since new of less than 200 hours, unless previously accomplished, replace at least one of the boards with a board not from the suspect batch in accordance with the instructions of Turboméca Mandatory Service Bulletin (MSB) 298 73 0809 Version A dated 12 February 2008.
                   2. Unless accomplished previously, replace all TU250 CS boards from the suspect batch with boards not from the suspect batch in accordance with the instructions of Turboméca MSB 298 73 0810 Version B dated 27 April 2009.
                Replacement of all TU250 CS boards, accomplished prior to the effective date of this Directive, in accordance with Turboméca MSB 298 73 0810 Version A dated
                12 February 2008 is acceptable for compliance with Requirement 2.
                The use of later Versions of the above MSBs, approved by the European Aviation Safety Agency (EASA), are acceptable for compliance with the requirements of this Directive.
                Note 3:  EASA AD 2009-0090 refers.
Compliance:     For Requirement 1 - Within 50 hours time in service from the effective date of this Directive.
                For Requirement 2 - During the next 500-hour routine inspection, or before
                30 November 2009, whichever occurs first.
                This Airworthiness Directive becomes effective on 12 May 2009.

Background:  Makila 1A and 1A1 ECUs incorporate a backup control law that fixes N1 (gas generator speed) at 65% when at least two of the three N2 (power turbine speed) signals are lost.  The intent is to limit the