AD/B737/119 Amdt 2 - Fuel Boost Pump Wiring

Administered by Department of Infrastructure, Transport, Regional Development, Communications, Sport and the Arts

Legislation au F2006B02821 Not in force Legislative Instrument

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Boeing 737 Series Aeroplanes

 

AIRWORTHINESS DIRECTIVE


For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B737/119 Amdt 1 and issues the following 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 aircraft 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/B737/119

Amdt 2


Fuel Boost Pump Wiring 3/2000

 

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

 

Requirement: 1. For all aeroplanes that have accumulated 50,000 or more hours total time in service as of the effective date of this Directive - Remove the fuel boost pump wiring from the in-tank conduit for the aft boost pumps in main tanks numbers 1 and 2 and 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 Notices 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 May1998 or Revision 2

dated 26 November 1998.

 

2.          For all aeroplanes that have accumulated less than 50,000 hours total time in service as of the effective date of this Directive - Remove the fuel boost pump wiring from the in-tank conduit for the aft boost pumps in main tanks numbers 1 and 2 and perform a detailed visual inspection to detect damage to the wiring, 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 May1998 or Revision 2 dated 26 November 1998.

 

3.          For all aeroplanes - Remove the fuel boost pump wiring from the in-tank conduit for the centre tank left and right boost pumps and perform a detailed visual inspection to detect damage to the wiring, 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 May1998 or Revision 2 dated 26 November 1998.

 

4.          For all aeroplanes - Remove the fuel boost pump wiring from the in-tank conduit for the aft boost pumps in main tanks numbers 1 and 2 and the centre tank left and right boost pumps and perform a detailed visual inspection to detect damage to the wiring, 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 May1998 or Revision 2 dated 26 November 1998.

 

 

5.          If red, yellow, blue or green wire insulation cannot be seen through the outer jacket of the electrical cable during the Requirement 1, 2, 3 or 4 inspections, 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 May1998 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.

 

6.          If Requirement 5.b is applied, repeat the Requirement 1, 2, 3 or 4 inspection, as applicable, and then install Teflon sleeving over the cable.

 

7.          If Requirement 5.c is applied, repeat the Requirement 1, 2, 3 or 4 inspection, as applicable, and then install Teflon sleeving over the cable.

 

8.          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 May1998 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.

 

9.          If Requirement 8.b is applied, repeat the Requirement 1, 2, 3 or 4 inspection, as applicable, and then install Teflon sleeving over the cable.

 

10.     If any evidence of electrical arcing but no evidence of fuel leakage is found on the removed cable during the Requirement 1, 2, 3 or 4 inspections, 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 May1998 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 to 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.

 

11.     If Requirement 10.b.(ii) is applied, repeat the Requirement 1, 2, 3 or 4 inspection, as applicable, and then install Teflon sleeving over the cable.

 

12.     If any evidence of fuel is found on the removed cable during the Requirement 1, 2, 3 or 4 inspections, 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 May1998 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.

 

13.     If Requirement 12.b.(ii) is applied, repeat the Requirement 1, 2, 3 or 4 inspection, as applicable, and then install Teflon sleeving over the cable.

 

14.     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 May1998 or Revision 2 dated 26 November 1998.

 

15.      Deleted.

 

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

 

Compliance: For Requirement 1 - Remains unchanged as ‘Prior to further flight after the effective date of the original issue of this Directive’.

 

For Requirement 2 - Remains unchanged as ‘Prior to the accumulation of 40,000 hours total time in service or within 14 days from the effective date of the original issue of this Directive, whichever is later’.

 

 

For Requirement 3:

 

  1. Model 737-300, 400 and 500 series aeroplanes - Remains unchanged as ‘Prior to the accumulation of 40,000 hours total time in service or within 14 days from the effective date of Amendment 1 of this Directive, whichever is later’.

 

b.     Model 737-100 and 200 series aeroplanes - Remains unchanged as ‘Prior to the accumulation of 40,000 hours total time in service or within 10 days from the effective date of Amendment 1 of this Directive, whichever is later’.

 

c.     All model aeroplanes - Remains unchanged as ‘Prior to the accumulation of 50,000 hours total time in service or within 5 days from the effective date of Amendment 1 of this Directive, whichever is later’.

 

For Requirement 4 - Prior to the accumulation of 30,000 hours total time in service or within 45 days from the effective date of Amendment 1 of this Directive, whichever is later and then at intervals not to exceed 30,000 hours time in service from the initial accomplishment of the inspection.

 

For Requirement 5 - Prior to further flight, immediately following the Requirement 1, 2, 3 or 4 inspection.

 

For Requirement 6 - Within 500 hours time in service after the cable reinstallation.

 

For Requirement 7 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

 

For Requirement 8 - Prior to further flight, immediately following the Requirement 1, 2, 3 or 4 inspection.

 

For Requirement 9 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

 

For Requirement 10 - Prior to further flight, immediately following the Requirement 1, 2, 3 or 4 inspection.

 

For Requirement 11 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

 

For Requirement 12 - Prior to further flight, immediately following the Requirement 1, 2, 3 or 4 inspection.

 

For Requirement 13 - Within 18 months or 6,000 hours time in service, which ever occurs first, after the cable replacement.

 

 

For Requirement 14 - Prior to further flight, immediately following the Requirement 1, 2, 3 or 4 inspection.

 

This Amendment becomes effective on 23 March 2000.

 

Background:  This amendment introduces minor formatting changes, makes the Requirement 4 inspection repetitive, which removes the optional Teflon sleeving terminating action, deletes Requirement 15 and adds ASB Revisions to the requirement statements.

 

Amendment 1 increased the range of affected aeroplanes and reduced some compliance times due to information obtained by the FAA since the issue of original telegraphic directives T98-10-51 and T98-11-51.

 

The FAA received reports of severe wear of fuel boost pump wiring on two model 737-200 aeroplanes that had accumulated 54,000 and 67,000 hours total time in service. The cause of this wear was attributed to chafing between the in-tank fuel boost pump wiring and the surrounding conduit inside the fuel tank. If the outer sleeving and the insulation is worn off the 115 volt alternating current conductor wiring, electrical arcing between the conductor and conduit could occur resulting in puncture of the conduit. Electrical arcing could also provide an ignition source inside the fuel tanks. Puncture of the conduit may also provide a path for fuel to leak from the fuel tank.

 

Actions required by this Directive are designed to detect and correct chafing between the fuel boost pump wiring and the surrounding conduit, therefore decreasing the likelihood of electrical arcing and consequent fire or explosion of the fuel tank.

 

This Directive is considered interim action, additional inspections may be required beyond those specified in this directive, especially if inspections required by the FAA AD reveal damage in low hour aircraft.

 


Amendment 1 to this Directive became effective on 19 May 1998. The original issue of this Directive became effective on 14 May 1998.

 

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.

Overview

The Boeing 737 Series Aeroplanes Airworthiness Directive AD/B737/119 Amendment 2, issued by the Civil Aviation Safety Authority (CASA) in 2000, addresses a critical safety concern related to the fuel boost pump wiring in Boeing 737 aircraft. This legislative instrument was enacted to ensure the safe operation of Boeing 737-100, -200, -300, -400, and -500 series aeroplanes by mitigating the risk of electrical arcing and subsequent fuel tank fire or explosion due to chafing of the fuel boost pump wiring. The directive was issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998. The policy objective of this directive is to mandate detailed visual inspections and corrective actions on the wiring to prevent unsafe conditions that could potentially lead to catastrophic failures. The directive applies to all Boeing 737 series aeroplanes, requiring inspections and corrective measures based on the total time in service of the aircraft.

Scope and Application

This Airworthiness Directive (AD) applies to all Boeing 737 series aeroplanes, including models 737-100, -200, -300, -400, and -500. The AD mandates specific actions to be taken concerning the fuel boost pump wiring to address safety concerns related to potential damage and electrical arcing that could lead to fuel tank fires or explosions. The directive requires the removal of fuel boost pump wiring from the in-tank conduit for various boost pumps, depending on the total time in service of the aeroplane, and detailed visual inspections to detect any damage to the wiring. Depending on the findings during these inspections, further actions such as installing Teflon sleeving, replacing cables, or verifying conduit integrity may be necessary. The AD specifies compliance timelines, which vary based on the findings and actions taken, and these timelines are to be met before further flight or within specified intervals of time in service. The AD extends across the Commonwealth of Australia and is enforced by the Civil Aviation Safety Authority (CASA). There are no exclusions or exemptions stated in the AD, meaning all applicable aircraft must adhere to the outlined requirements. The AD incorporates subordinate instruments by referencing Boeing Alert Service Bulletins and Notices of Status Change, which detail the specific procedures to be followed during inspections and corrective actions.

Key Provisions

The key provisions of the Boeing 737 Series Aeroplanes Airworthiness Directive (AD) AD/B737/119 Amdt 2, issued by the Civil Aviation Safety Authority (CASA) delegate, focus on the inspection and maintenance of the fuel boost pump wiring for various models of Boeing 737 aeroplanes. According to the directive, all model 737-100, -200, -300, -400, and -500 series aeroplanes are subject to specific requirements concerning the removal, inspection, and possible replacement of the fuel boost pump wiring to prevent potential electrical arcing and consequent fire or explosion of the fuel tanks. These requirements are detailed in the directive and must be followed in accordance with the procedures specified in Boeing Alert Service Bulletin (ASB) 737-28A1120, as revised by subsequent Notices of Status Change (NSC). The AD imposes several obligations on the operators and maintainers of the affected aeroplanes. Firstly, aeroplanes that have accumulated 50,000 or more hours total time in service must undergo a detailed visual inspection of the fuel boost pump wiring as specified in the directive. Secondly, aeroplanes with less than 50,000 hours total time in service must also undergo a detailed visual inspection of the wiring, in line with the procedures outlined in Boeing ASB 737-28A1120. Thirdly, all aeroplanes are required to remove the wiring from the in-tank conduit and inspect it for damage. Depending on the findings during the inspection, further actions such as installing Teflon sleeving, replacing the electrical cable, or verifying the integrity of the conduit may be necessary. The directive sets specific compliance times for these requirements. For aeroplanes with 50,000 or more hours total time in service, compliance must be achieved prior to the accumulation of 50,000 hours total time in service or within 5 days from the effective date of Amendment 1 of this Directive, whichever is later. For aeroplanes with less than 50,000 hours total time in service, compliance must be achieved within 14 days from the effective date of Amendment 1 of this Directive. Failure to adhere to these compliance deadlines may result in the aeroplane being deemed unairworthy, which could lead to significant operational disruptions and potential safety risks. In terms of penalties and consequences, the AD itself does not explicitly state civil or criminal penalties for non-compliance. However, non-compliance with CASA directives can lead to enforcement actions, which may include fines, suspension or revocation of airworthiness certificates, and other regulatory actions. These actions are governed by the Civil Aviation Act 1988 and the Civil Aviation Regulations 1988. The seriousness of the potential consequences underscores the importance of adhering to the AD's requirements to ensure the continued airworthiness and safety of the affected aircraft.

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