AD/CF6/68 Compressor Discharge Pressure Spring (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 - CF6 Series

AD/CF6/68 Compressor Discharge Pressure Spring 12/2007

Applicability:

General Electric Company Aircraft Engine Group (GEAE) CF6-45A, 45A2, -50A,
-50C, -50CA, -50C1, -50C2, -50C2B, -50C2D, -50C2F, -50C2R, -50E, -50E1, -50E2, and -50E2B turbofan engines that have a main engine control (MEC) with a part number (P/ N) specified in Table 1 of this AD installed.

Note 1:  These engines are installed on, but not limited to, Airbus A300 series airplanes, McDonnell Douglas DC-10, KC-10, and MD-10 series airplanes, and Boeing 747 series aeroplanes.

Table 1. - Affected Woodward and GEAE
P/Ns for MECs by Engine Model Series

Engine Model Series	Woodward P/N	GEAE P/N
CF6-50A, -50C, -50CA, -50C1, -50C2, 50C2B, -50C2D, -50C2F, -50C2R	8062-275	9070M55P42
8062-279	9070M55P44
8062-287	9070M55P49
8062-289	9070M55P51
8062-819	9070M55P101
8062-822	9070M55P102
8062-824	9070M55P103
8062-823	9070M55P104
8062-826	9070M55P105
8062-827	9070M55P106
8062-828	9070M55P107
8062-829	9070M55P108
CF6-45A, -45A2, -50E, -50E1, -50E2, -50E2B	8062-276	9187M29P10
8062-280	9187M29P11
8062-290	9187M29P14

8062-291	9187M29P15
8062-817	9187M29P100
8062-820	9187M29P101
8062-896	9187M29P22
8062-897	9187M29P23
8062-898	9187M29P20
8062-899	9187M29P21

Requirement:

1.    For CF6-50A model engines and -50C series engines that have an MEC that has a P/N listed in Table 1 of this AD, replace the compressor discharge pressure (CDP) restoring spring assembly as follows in Table 2 of this AD.

Table 2. - Compliance Schedule for CF6-50A and -50C Engines

If the CDP restoring spring assembly in your MEC	Then	By	Use
(1) Was already replaced using GEAE CF6-50 S/B 73-0119, dated 21 March 2005.	Re-mark the MEC.	The next time the MEC is routed for repair such as the next MEC shop visit.	Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0119, Revision 02, dated 9 March 2007.
(2) Was already replaced within 10,000 or fewer hours time-in-service (TIS) before the effective date of this AD, and the replacement spring assembly (P/N 3018-248) had zero hours TIS.	Replace the spring assembly and re-mark the MEC.	The first MEC shop visit or engine shop visit after the MEC exceeds 10,000 hours TIS, but do not exceed 20,000 hours TIS.	Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0119, Revision 02.
(3) Has more then 10,000 hours TIS.	Replace the spring assembly and re-mark the MEC.	The next MEC shop visit or engine shop visit whichever occurs first.	Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0119, Revision 02.

2.    For CF6-45A series and -50E series engines that have an MEC that has a P/N listed in Table 1 of this AD, replace the CDP restoring spring assembly as follows in Table 3 of this AD.

Table 3. - Compliance Schedule for CF6-45A and -50E Engines

If the CDP restoring spring assembly in your MEC	Then	By	Use
(1) Was already replaced within 10,000 or fewer hours time-in-service (TIS) before the effective date of this AD, and the replacement spring assembly (P/N 3018-248) had zero hours TIS.	Replace the spring assembly and re-mark the MEC.	The first MEC shop visit or engine shop visit after the MEC exceeds 10,000 hours TIS, but do not exceed 20,000 hours TIS.	Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0120, dated 21 March 2007.
(2) Has more then 10,000 hours TIS.	Replace the spring assembly and re-mark the MEC.	The next MEC shop visit or engine shop visit whichever occurs first.	Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0120.

Definition:  For the purpose of this AD, a shop visit is induction of the engine or MEC into the shop for any cause.

3.    Do not install an MEC that:

a)    Has not complied with SB No. CF6-50 S/B 73-0119, Revision 02, or earlier revision, or SB No. CF6-50 S/B 73-0120; or

b)    Has not had the CDP restoring spring replaced with a spring assembly, P/N 3018-248, or FAA-approved equivalent spring assembly, within the previous 10,000 hours of MEC operation.

Note 2:  FAA AD 2007-19-06 Amdt 39-15196 dated 7 September 2007 refers.

Compliance:

1.    As detailed in Table 2 of this AD.

2.    As detailed in Table 3 of this AD.

3.    From the effective date of this AD.

This Airworthiness Directive becomes effective on 22 November 2007.
Background:	The FAA reports that there have been five events involving fractured CDP restoring spring assembly.  The issuing of this AD is intended to prevent loss of engine thrust control that could lead to loss of control of the aeroplane.

David Punshon
Delegate of the Civil Aviation Safety Authority

2 October 2007