COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
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/B737/135 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 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.
AD/B737/135
Amdt 1
Refuel Valve Actuator Suppression Diodes 9/2000
Applicability: Model 737-100, -200, -300, -400 and -500 series aeroplanes, line numbers 1 through
3016.
Requirement: 1. For Group 1 aeroplanes, as identified in Boeing Service Bulletin (SB) 737-28- 1115, dated 4 March 1999 or Revision 1 dated 11 May 2000 - Install a transient suppression diode, part number (P/N) 69-58806-4, in the wire bundle (W264) of the refuelling valve-to-float switch of each fuel tank, in accordance with either service bulletin.
2. For Groups 2, 3, and 4 aeroplanes, as identified in SB 737-28-1115 or Revision 1 dated 11 May 2000 - Replace the existing transient suppression diode, P/N 69- 58806-1 or 69-58806-3, installed in the wire bundle (W264) of the refuelling valve-to-float switch of each fuel tank, with an improved diode, P/N 69-58806-4, in accordance with either service bulletin.
3. Following accomplishment of either Requirements 1 or 2, perform a functional test to verify proper installation of each diode in accordance with SB 737-28-1115 or Revision 1 dated 11 May 2000. If any discrepancy is detected during any functional test replace the discrepant diode and repeat the functional test.
4. Transient suppression diodes having either P/N 69-58806-1 or 69-58806-3 may not be installed on any aeroplane.
Note: FAA AD 99-23-20 Amdt 39-11416 and Alternate Method of Compliance (AMOC) 140S-00-188 dated 26 April 2000 refer.
Compliance: For Requirement 1 - Remains unchanged as “Within 12 months from the effective date of the original issue of this Directive”.
For Requirement 2 - Remains unchanged as “Within 12 months from the effective date of the original issue of this Directive”.
For Requirement 3 - Prior to further flight.
For Requirement 4 - As of the effective date of this Directive.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
This Amendment becomes effective on 7 September 2000.
Background: Boeing has advised of two incidents of electrical fire during fuelling of Boeing Model 737 aeroplanes. Investigation revealed that these incidents were due to a short circuit and overheating of a transient suppression diode.
The original issue of this Directive was intended to prevent the short circuit and overheating from occurring. Those conditions, if not corrected, could result in electrical arcing and ignition of fuel vapours at the refuelling receptacle for the fuel tanks, together with the possibility of fire during fuelling.
This amendment introduces an AMOC which allowed a revised SB to be utilised.
The original issue of this Airworthiness Directive became effective on 24 February 2000.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 27 July 2000
The above AD is notified in the Commonwealth of Australia Gazette on 9 August 2000.
Overview
The Civil Aviation Regulations 1998 were enacted to regulate the safety and efficiency of civil aviation in Australia, including the issuance of airworthiness directives to address specific safety concerns. This legislative instrument, specifically PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES, targets Boeing 737 Series Aeroplanes to address a safety issue identified with the transient suppression diodes in the refuelling valve actuator system. The problem arose from incidents of electrical fires during refuelling due to short circuits and overheating of the diodes, which could potentially lead to catastrophic outcomes. The Civil Aviation Safety Authority (CASA) was the enacting body, issuing an airworthiness directive to mandate corrective actions to ensure the safety of these aircraft. The policy objective behind this directive is to prevent unsafe conditions that could lead to accidents, thereby safeguarding the public and maintaining high safety standards in civil aviation.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, applies to all Boeing 737 series aeroplanes, including models 737-100, -200, -300, -400, and -500, within specified line numbers. This legislation mandates particular actions to address identified safety concerns, particularly regarding the transient suppression diodes in the refuelling valve-to-float switch of each fuel tank. The directive is applicable to all operators of these aircraft, ensuring compliance with safety standards set forth by CASA. It is a Commonwealth regulation, extending its jurisdiction across the entire nation. There are no specific exclusions or exemptions mentioned in the directive, which means it applies universally to the specified aircraft within the stipulated parameters. The directive allows for modifications and compliance through subordinate instruments, such as service bulletins and alternate methods of compliance, to adapt to evolving safety standards and technological advancements.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, outlines the Airworthiness Directives (AD) issued by the Civil Aviation Safety Authority (CASA) concerning Boeing 737 series aeroplanes. This particular AD, AD/B737/135, addresses a safety concern related to the transient suppression diodes in the refuelling valve actuators. The AD was issued to prevent the occurrence of electrical fires during the fuelling of Boeing 737 aeroplanes by requiring modifications to the transient suppression diodes in the refuelling valve-to-float switch of each fuel tank. The AD applies to Model 737-100, -200, -300, -400, and -500 series aeroplanes, line numbers 1 through 3016 (Section 1). For Group 1 aeroplanes, the directive mandates the installation of a new transient suppression diode (P/N 69-58806-4) in the wire bundle (W264) of the refuelling valve-to-float switch of each fuel tank. For Groups 2, 3, and 4 aeroplanes, it requires replacing the existing transient suppression diode (P/N 69-58806-1 or 69-58806-3) with an improved diode (P/N 69-58806-4). After completing either Requirement 1 or 2, a functional test must be performed to verify the proper installation of each diode, with any discrepancies requiring replacement and retesting (Section 2). The directive also prohibits the installation of transient suppression diodes having P/N 69-58806-1 or 69-58806-3 on any aeroplane (Section 3). Compliance with these requirements is set at specific timelines: within 12 months from the effective date for Requirements 1 and 2, prior to further flight for Requirement 3, and as of the effective date for Requirement 4 (Section 4).
Entities governed by this AD, such as aircraft operators and maintenance providers, are obligated to ensure that the specified actions are taken on applicable Boeing 737 aeroplanes. This includes installing or replacing the transient suppression diodes as required and performing functional tests to verify proper installation. Operators must ensure that the specified modifications are completed within the stipulated timeframes, and maintenance personnel must follow the instructions provided in the relevant Boeing Service Bulletins to ensure compliance. These obligations are critical to maintaining the airworthiness of the aircraft and preventing potential fire hazards during the refuelling process.
Failure to comply with this Airworthiness Directive can result in significant consequences. Non-compliance may lead to grounding of the affected aircraft until the required modifications are made, potentially resulting in operational disruptions and financial losses. Additionally, operating an aircraft that does not meet the requirements of this AD may constitute a breach of civil aviation safety regulations, which can result in penalties under the Civil Aviation Act 1988. The specific penalties for non-compliance are not detailed in the AD itself but can include fines, enforcement actions, or other legal repercussions under the applicable aviation legislation. It is essential for all parties involved to adhere to the AD to ensure the safety and airworthiness of the Boeing 737 series aeroplanes.