COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Boeing 737 Series Aeroplanes
AD/B737/62
Amdt 1
Main Fuel Tank Float Switch Electrical Harness 2/94
Applicability: All model 737 series aeroplanes identified in Boeing Service Letters 737-SL-28-36 and 737-SL-28-42 dated 30 November 1990 and 15 December 1992 respectively.
Requirement: 1. For aircraft identified in Service Letter 737-SL-28-36 inspect the wing main tank float switch electrical conduit for fuel leaks and condensation build up in accordance with the Service Letter 737-SL-28-36. If evidence of fuel leakage or water condensation is found then, before the next flight, purge and install a new vapour seal assembly in accordance with the Service Letter.
2. For aircraft identified in Service Letter 737-SL-28-42 inspect the wing main tank float switch electrical conduit for fuel leaks and condensation build up in accordance with the Service Letter 737-SL-28-36. If evidence of fuel leakage or water condensation is found then, before the next flight, purge and install a new vapour seal assembly in accordance with Service Letter 737-SL-28-36.
3. Fill the interior of the wing main tank float switch electrical conduits with grease in accordance with either:
- Boeing Service Letter 737-SL-28-42 dated 15 December 1992,
b. Boeing Service Letter 737-SL-28-42A dated 15 July 1993; or
c. Ansett Airlines Engineering Release B73-28-10-6B.
Note: FAA AD 93-17-02 Amdt 39-8672 refers.
Compliance: 1 - The Compliance was originally prior to 7 February 1992, and thereafter at intervals not exceeding 1500 hours time in service.
This amendment is effective from 3 February 1994 and thereafter at intervals not exceeding 1500 hours time in service.
2 - Prior to 1 April 1994 and thereafter at intervals not exceeding 1500 hours time in service.
3 - Prior to 1 January 1997. This Requirement is considered terminating action for the repetitive 1500 hour inspections.
Background: Several incidents of wing main tank float switch electrical conduit failure have been reported. This condition, if not corrected, could result in a fuel leak from the wing main tank which could propagate down the wing leading edge cavity to the respective engine tail pipe, and cause an external fire under the wing.
This amendment introduces initial and repetitive inspections for additional aeroplanes and provides terminating action for the repetitive inspections.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Overview
The Civil Aviation Regulations 1998, specifically within Part 39 - 105 under the Civil Aviation Safety Authority, encompasses a series of airworthiness directives aimed at maintaining the safety standards of aircraft operations. One such directive, AD/B737/62, was introduced to address the problem of fuel leaks and condensation build-up in the wing main tank float switch electrical conduit of Boeing 737 series aeroplanes. This was necessitated by several reported incidents where failure of the electrical conduit could lead to a fuel leak, potentially resulting in an external fire under the wing. The directive was enacted by the Civil Aviation Safety Authority and its policy objective is to ensure the ongoing safety and airworthiness of the aircraft by mandating specific inspection and maintenance actions. Compliance with these directives is critical to preventing such hazardous conditions from occurring.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, pertains to Boeing 737 series aeroplanes and their maintenance and safety standards. This particular directive, AD/B737/62 Amendment 1, focuses on the main fuel tank float switch electrical harness for aircraft identified in Boeing Service Letters 737-SL-28-36 and 737-SL-28-42, dated 30 November 1990 and 15 December 1992 respectively. The directive applies to all operators of Boeing 737 series aeroplanes that fall within the specified service letters. It mandates regular inspections for fuel leaks and condensation build-up in the electrical conduits of the wing main tank float switch, with corrective actions required if such issues are detected. The directive further stipulates that the conduits should be filled with grease to mitigate potential risks, and outlines specific compliance intervals, with the requirement becoming a terminating action after a certain period. This legislation applies on a national level within Australia, ensuring adherence to safety standards across all operators of the affected aircraft.
Key Provisions
The main operative sections of the Civil Aviation Regulations 1998, specifically Part 39 - 105, focus on issuing Airworthiness Directives (AD) to ensure the safety of aircraft in operation. Section 39-105 addresses Boeing 737 Series Aeroplanes, with Amendment 1 targeting the Main Fuel Tank Float Switch Electrical Harness (AD/B737/62). This AD applies to all model 737 series aeroplanes identified in Boeing Service Letters 737-SL-28-36 and 737-SL-28-42, dated 30 November 1990 and 15 December 1992 respectively. The directive requires that these aircraft undergo specific inspections and maintenance procedures to address potential fuel leaks and condensation build-up in the wing main tank float switch electrical conduits. If such issues are detected, the aircraft must be purged and fitted with a new vapour seal assembly before the next flight. Additionally, the interior of the wing main tank float switch electrical conduits must be filled with grease as per specified Boeing Service Letters or Ansett Airlines Engineering Release.
The obligations imposed by this AD include thorough inspections of the specified aircraft's electrical conduits at designated intervals to ensure there are no fuel leaks or condensation build-up. Operators must adhere to the outlined inspection and maintenance procedures as detailed in the relevant Boeing Service Letters and Engineering Release. Compliance is mandatory, with initial inspections required before 7 February 1992 and subsequent inspections at intervals not exceeding 1500 hours of time in service. For the repetitive inspections, compliance is required before 1 April 1994, and thereafter at intervals not exceeding 1500 hours. The directive also specifies that the grease filling requirement is a terminating action for the repetitive 1500-hour inspections, meaning it is a one-time action required before 1 January 1997.
Failure to comply with the AD may result in severe consequences, as the directive addresses potential fuel leaks that could lead to external fires under the wing. Although specific penalties are not detailed in the text, non-compliance with ADs generally leads to enforcement actions by the Civil Aviation Safety Authority (CASA). These actions can include fines, suspension or revocation of aircraft operating certificates, and other regulatory penalties. Civil and criminal liabilities may also arise if non-compliance results in accidents or incidents, potentially leading to substantial legal and financial repercussions for the operators.