AD/TPE 331/63 Amdt 1 Fuel Control Unit Drive Spline (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/TPE 331/63 and issues the following 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.

AlliedSignal (Garrett/AiResearch) Turbine Engines - TPE 331 Series

AD/TPE 331/63 Amdt 1 Fuel Control Unit Drive Spline 8/2008 TX

Applicability:

Honeywell International Inc. TPE331-1, -2, -2UA, -3U, -3UW, -5, -5A, -5AB, -5B,
-6, -6A, -10, -10AV, -l0GP, -10GT, -l0P, -10R, -l0T, -l0U, -10UA, -10UF, -10UG,
-10UGR, -10UR, -11U, -12JR, -12UA, -12UAR, and -12UHR turboprop engines with the part numbers (P/Ns) of Woodward fuel control unit (FCU) assemblies, listed in Requirements 3, 4 and 5 of this AD, installed.

Requirement:

1.    Initial Inspection of Engines With Affected FCU Assemblies

a.     Perform an initial dimensional inspection of the fuel control drive for wear or damage.  Information on spline inspection can be found in Section 72-00-00 of the applicable maintenance manuals.

b.    Repair or replace the fuel pump, if the spline fails the dimensional inspection, with any serviceable fuel pump.

c.     Repair or replace the FCU assembly, if the splines fail the dimensional inspection, with a serviceable modified FCU assembly.

2.    Repetitive Inspections of Engines With Affected FCU Assemblies

a.     Perform repetitive dimensional inspections of the fuel control drive, for wear or damage. Information on spline inspection can be found in Section
72-00-00 of the applicable maintenance manuals.

b.    Repair or replace the fuel pump, if the spline fails the dimensional inspection, with any serviceable fuel pump.

c.     Repair or replace the FCU assembly if the splines fail the dimensional inspection, with a serviceable modified FCU assembly.

3.    TPE331-l, -2, and -2UA Series Engines

Replace Woodward FCU assemblies, P/Ns 869199-13/ -20/ -21/ -22/ -23/ -24/
-25/ -26/ -27/ -28/ -29/ -31/ -32/ -33/ -34, and -35, with a serviceable, modified FCU assembly.

Information on replacement FCU assembly P/Ns, configuration management, rework, and replacement information, can be found in Honeywell Alert Service Bulletin (ASB) No. TPE331-A73- 0271, Revision 2 dated 28 August 2006.

4. TPE331-3U, -3UW, -5, -5A, -5AB, -5B, -6, -6A, -10AV, -10GP, -10GT, -10P and -l0T Series Engines

Replace Woodward FCU assemblies, P/Ns 893561-7/ -8/ -9/ -10/ -11/ -14/ -15/
-16/ - 20/ -26/ -27, and -29, and P/Ns 897770-1/ -3/ -7/ -9/ -10/ -11/ -12/ -14/ -15/ -16/ -25/ -26/, and -28, with a serviceable, modified FCU assembly.

Information on replacement FCU assembly P/Ns, configuration management, rework, and replacement information, can be found in Honeywell ASB No. TPE331-A73-0262, Revision 2 dated 17 June 2005.

5.    TPE331-l0, -10R, -l0U, -10UA, -10UF, -10UG, -10UGR, -10UR, -11U, -12JR, -12UA, -12UAR, and -12UHR Series Engines

Replace Woodward FCU assemblies, P/Ns 897375-2/ -3/ -4/ -5/ -8/ -9/ -10/ -11/
-12/ -13/ -14/ -15/ -16/ -17/ -19/ -21/ -24/ -25/ -26, and -27, and P/Ns 897780-1/
-2/ -3/ -4/ -5/ -6/ -7/ -8/ -9/ -10/ -11/ -14/ -15/ -16/ -17/ -18/ -19/ -20/ -21/ -22/
-23/ -24/ -25/ -26/ -27/ -30/ -32/ -34/ -36/ -37, and -38, and P/Ns 893561-17/ -18, and -19, with a serviceable, modified FCU assembly.

Information on replacement FCU assembly P/Ns, configuration management, rework, and replacement information, can be found in Honeywell ASB No. TPE331-A73-0254, Revision 2 dated 17 June 2005.

Definitions:

For the purposes of this AD:

A “serviceable, modified FCU assembly” for engines affected by this AD is an FCU assembly with a P/N not listed in this AD.

The “fuel control drive” is a series of mating splines located between the fuel pump and fuel control governor, consisting of the following four drive splines:  The fuel pump internal spline, the fuel control external “quill shaft” spline, and the stub shaft internal and external splines.

A “removal for cause that requires return”, for engines affected by requirement 3, 4 or 5 of this AD, is an FCU assembly that has displayed an unserviceable or unacceptable operating condition requiring the FCU to be removed from service and sent to a repair or overhaul shop.

Optional Method of Compliance for TPE331 Series Engines
Installed On Single-Engine Aeroplanes:

As an optional method of compliance to requirement 3, 4 or 5 of this AD, for TPE331 series engines installed on single-engine aeroplanes, having an affected Woodward FCU assembly perform the following steps as necessary:

a.    Continue repetitive dimensional inspections of the fuel control drive, for wear or damage as specified in requirement 2 of this AD.

b.    Repair or replace the fuel pump or FCU assembly if the splines fail the dimensional inspection, with any serviceable fuel pump or FCU assembly.

Alternative Method of Compliance (AMOC):

Revision 2 of Honeywell Service Bulletin TPE331-A73-0271 is approved as an alternative means of compliance with Requirements 1(c), 2(c) and 3 of this AD. Paragraph 2A of Honeywell Service Bulletin TPE331-A73-0271 Revision 2 provides for a one-time extension to the compliance time and Paragraph 2B provides for an AMOC to the reference Requirements.  One time extensions for engine previously in compliance with Paragraph 2A of the referenced SB will remain until expired.

Terminating Action:

Performing an FCU assembly replacement as specified in requirement 3, 4 or 5 of this AD, is terminating action for the initial and repetitive inspections required by this AD.

Note 1:  Information pertaining to operating recommendations for applicable engines after a fuel control drive failure is contained in OI 331-12R5 dated 10 July 2006, for multi-engine aeroplanes and in OI 331-18R3 dated 10 July 2006, for single-engine aeroplanes.

Note 2:  FAA AD 2006-15-08 Amdt 39-14688 dated 14 July 2006 refers.

Compliance:

1.    Remains unchanged as detailed in the original issue of this AD as: At the next scheduled inspection of the fuel control drive, but within 1,000
hours-in-service after 28 September 2006, unless previously accomplished.

2.    Repetitively within 1,000 hours since-last-inspection.

3.    The next time the FCU assembly is removed for a cause that requires return, or when the FCU assembly requires overhaul, but not later than December 31, 2012.

4.    The next time the FCU assembly is removed for a cause that requires return, or when the FCU assembly requires overhaul, but not later than December 31, 2012.

5.    The next time the FCU assembly is removed for a cause that requires return, or when the FCU assembly requires overhaul, but not later than December 31, 2012.

This Amendment becomes effective on 23 June 2008.

Background:

This AD results from reports of loss of fuel control unit drive leading to engine overspeed, over torque, uncontained rotor failure and asymmetric thrust in multiengine aeroplanes.  The actions detailed in this AD are to prevent destructive overspeed that could result in uncontained rotor failure and damage to the aeroplane.

This amendment provides an AMOC to replacement of parts failing the spline dimensional check.

The original issue of this AD became effective on 28 September 2006.

James Coyne
Delegate of the Civil Aviation Safety Authority

16 June 2008