AD/CF34/15 Fuel Metering Unit Wiring (Cth)

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.

General Electric Turbine Engines - CF34 Series

AD/CF34/15 Fuel Metering Unit Wiring 4/2008

Applicability:	CF34 series engines as follows:
a.    CF34-8C1/-8C5/-8C5B1/-8E5/- 8E5A1 turbofan engines, with General Electric (GE) fuel metering unit (FMU) part number (P/N) 4120T01P02, serial numbers (S/N) WYG89156 through WYGB4222, and Woodward Governor FMU Vendor Identification Number (VIN) 8061-926, S/Ns 11954378 through 15140071.
b.    CF34-10E series turbofan engines, with GE FMU P/N 2043M10P05, S/Ns WYGA3251 through WYGB4085, and Woodward Governor FMU VIN 8063-884, S/Ns 13335695 through 15028283.
Note 1:  These engines are know to be installed on, but not limited to, aeroplanes as follows:
a.    CF34-8C1/-8C5/-8C5B1 turbofan engines - Bombardier Inc. Model CL-600-2C10 (CRJ-700 & -701) and CL-600-2D24/-2D15 (CRJ-900) model aeroplanes.
b.    CF34-8E5/-8E5A1 turbofan engines - Embraer ERJ 170-100/-200 series aeroplanes.
c.    CF34-10E series turbofan engines - Embraer ERJ 190-100/-200 series aeroplanes.
Requirement:	1.    Unless previously accomplished , perform a onetime test of the FMU for a miswired (reversed polarity) condition of the input wires to the overspeed solenoid using paragraph 3A of the Accomplishment Instructions of following GE Service Bulletins (SB), as applicable:
a.     SB CF34-8C-AL S/B 73-0030 Revision 3, dated 1 November 2007,
b.    SB CF34-8E-AL S/B 73-0015, Revision 3, dated 1 November 2007, or
c.     SB . CF34-10E S/B 72-0067, Revision 2, dated 28 August 2007.
2.    If the FMU fails the test, remove the FMU.

Actions accomplished prior to the effective date of this Directive in accordance with the following SBs are acceptable for compliance with this Directive.
a.     SB CF34-8C-AL S/B 73-0030, original issue dated 25 May 2007, Revision 1, dated 19 July 2007 or Revision 2, dated 28 August 2007;
b.    SB CF34-8E-AL S/B 73-0015, original issue, dated 1 June 2007, Revision 1, dated 19 July 2007, or Revision 2, dated 28 August 2007; or
c.     SB . CF34-10E S/B 72-0067, original issue dated 7 June 2007 or Revision 1, dated 26 July 2007.
Later revisions of the SBs listed in Requirement 1, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-05-01, are considered acceptable for compliance with the equivalent requirements of this Directive.
Note 2:  FAA AD 2008-05-01 Amdt 39-15395 refers.
Compliance:	For Requirement 1 - Within 2,200 hours time in service after the effective date of this Directive, but not to exceed 24 months after the effective date of this Directive.
For Requirement 2 - Before further operation of the engine.
This Airworthiness Directive becomes effective on 10 April 2008.
Background:	The FAA has advised of the discovery of miswired FMU overspeed solenoids in the field which could prevent the engine from failing to shutdown during an overspeed and which may lead to uncontained engine failure.  This Directive requires a one time test of the FMU for a miswired (reversed polarity) condition of the input wires to the overspeed solenoid.

David Punshon
Delegate of the Civil Aviation Safety Authority

29 February 2008