Boeing 737 Series Aeroplanes

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 39.1 (1) of CAR 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 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.

AD/B737/138 Fuel Boost Pump Wiring 3/2000

Applicability: All model 737-100, -200, -300, -400 and -500 series aeroplanes.

Requirement: 1. Unless previously accomplished in accordance with AD/B737/119, Amdt 1 or Amdt 2; or AD/B737/121 or Amdt 1, remove the fuel boost pump wiring from the in-tank conduit for the aft boost pumps in main tanks numbers 1 and 2 and centre tanks left and right boost pumps; then perform a detailed visual inspection to detect damage of the wiring, in accordance with the procedures specified in Boeing Alert Service Bulletin (ASB) 737-28A1120 dated 24 April 1998, as revised by Notice of Status Change (NSC) 01 dated 7 May 1998, NSC 02 dated 8 May 1998 and NSC 03 dated 9 May 1998; ASB 737-28A1120 Revision 1

dated 28 May 1998 or Revision 2 dated 26 November 1998.

2.          If red, yellow, blue or green wire insulation cannot be seen through the outer jacket of the electrical cable during the Requirement 1 inspection, accomplish the following actions in accordance with the procedures specified in Boeing ASB 737-28A1120 dated 24 April 1998, as revised by NSC 01 dated 7 May 1998, NSC 02 dated 8 May 1998 and NSC 03 dated 9 May 1998; ASB 737-28A1120 Revision 1 dated 28 May 1998 or Revision 2 dated 26 November 1998.

1. Install Teflon sleeving over the electrical cable and reinstall the cable, or

b.    Reinstall the electrical cable without Teflon sleeving over the cable, or

c.    Replace the electrical cable with new cable without Teflon sleeving.

3.          If Requirement 2.b is applied, repeat the Requirement 1 inspection and then install Teflon sleeving over the cable.

4.          If Requirement 2.c is applied, repeat the Requirement 1 inspection and then install Teflon sleeving over the cable.

5.          If red, yellow, blue or green wire insulation can be seen through the outer jacket of the electrical cable during the Requirement 1, 2, 3 or 4 inspections, but no evidence of electrical arcing is found, accomplish the following actions in accordance with the procedures specified in Boeing ASB 737-28A1120 dated 24 April 1998, as revised by NSC 01 dated 7 May 1998, NSC 02 dated 8 May 1998 and NSC 03 dated 9 May 1998; ASB 737-28A1120 Revision 1 dated 28 May 1998 or Revision 2 dated 26 November 1998:

1. Replace the electrical cable with a new cable, install Teflon sleeving over the cable and reinstall the cable, or

b.    Replace the electrical cable with a new cable without Teflon sleeving.

6.          If Requirement 5.b is applied, repeat the Requirement 1 inspection and then install Teflon sleeving over the cable.

7.          If any evidence of electrical arcing, but no evidence of fuel leakage, is found on the removed cable during the Requirement 1 inspection, accomplish the following actions in accordance with the procedures specified in Boeing ASB 737-28A1120 dated 24 April 1998, as revised by NSC 01 dated 7 May 1998, NSC 02 dated 8 May 1998 and NSC 03 dated 9 May 1998; ASB 737-28A1120 Revision 1 dated 28 May 1998 or Revision 2 dated 26 November 1998:

1. Verify the integrity of the conduit in accordance with the instructions contained in either NSC 03, ASB 737-28A1120 Revision 1 or Revision 2 of the ASB, and

b.    Accomplish either of the following actions:

(i)       Replace the damaged electrical cable with a new cable, install Teflon sleeving over the cable and reinstall the cable, or

(ii)     Replace the electrical cable with a new cable without Teflon sleeving.

8.          If Requirement 7.b.(ii) is applied, repeat the Requirement 1 inspection and then install Teflon sleeving over the cable.

9.          If any evidence of fuel is found on the removed cable during the Requirement 1 inspection, accomplish the following actions in accordance with the procedures specified in Boeing ASB 737-28A1120 dated 24 April 1998, as revised by NSC 01 dated 7 May 1998, NSC 02 dated 8 May 1998 and NSC 03 dated 9 May 1998; ASB 737-28A1120 Revision 1 dated 28 May 1998 or Revision 2 dated 26 November 1998:

1. Replace the conduit section where the arcing was found, and

b.    Accomplish either of the following actions:

(i)       Replace the damaged electrical cable with a new cable, install Teflon sleeving over the cable and reinstall the cable, or

(ii)     Replace the electrical cable with a new cable without Teflon sleeving.

10.     If Requirement 9.b.(ii) is applied, repeat the Requirement 1 inspection and then install Teflon sleeving over the cable.

11.     For Groups 1 and 2 aeroplanes, as identified in Boeing ASB 737-28A1120 dated 24 April 1998, replace the case ground wire with a new wire in accordance with Boeing ASB 737-28A1120 dated 24 April 1998, as revised by NSC 01 dated 7 May 1998, NSC 02 dated 8 May 1998 and NSC 03 dated 9 May 1998; ASB 737- 28A1120 Revision 1 dated 28 May 1998 or Revision 2 dated 26 November 1998.

Note: FAA AD 99-21-15 Amdt 39-11360 refers.

Compliance: For Requirement 1 -

1. For aeroplanes having line numbers 1 through 3072 that have accumulated less than 20,000 hours total time in service as of the 15 October 1998, at the earlier of the times specified in sub paragraphs (i) or (ii) below and thereafter at intervals not to exceed 30,000 time in service:

(i)       Prior to the accumulation of 20,000 hours total time in service or within 60 days from the effective date of this Directive, whichever occurs later.

(ii)     Within 24 months after the effective date of this Directive.

b.    For aeroplanes having line numbers 3073 and subsequent - Prior to the accumulation of 30,000 hours total time in service and thereafter at intervals not to exceed 30,000 hours time in service.

For Requirement 2 - Prior to further flight, immediately following the Requirement 1 inspection.

For Requirement 3 - Within 500 hours time in service after the cable reinstallation.

For Requirement 4 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

For Requirement 5 - Prior to further flight, immediately following the Requirement 1 inspection.

For Requirement 6 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

For Requirement 7 - Prior to further flight, immediately following the Requirement 1 inspection.

For Requirement 8 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

For Requirement 9 - Prior to further flight, immediately following the Requirement 1 inspection.

For Requirement 10 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

For Requirement 11 - Prior to further flight, immediately following the Requirement 1 inspection.

This Airworthiness Directive becomes effective on 23 March 2000.

Background:   This Directive is complementary to AD/B737/119 and AD/B737/121, and introduces a similar inspection for aeroplanes that have accumulated less than 20,000 hours total time in service.

Eugene Paul Holzapfel

Delegate of the Civil Aviation Safety Authority 15 February 2000

The above AD is notified in the Commonwealth of Australia Gazette on 23 February 2000.