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 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 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/B737/152 Centre Fuel Tank - Limitations 6/2001
DM
Applicability: All Model 737 series aeroplanes.
Requirement: Revise the Limitations Section of the Aircraft Flight Manual (AFM) to include the following information:
For ground operation, centre tank fuel pump switches must not be positioned to "ON" unless the centre tank fuel quantity exceeds 1,000 pounds (453 kilograms), except when defuelling or transferring fuel.
Centre tank fuel pump switches must be positioned to "OFF" when both centre tank fuel pump low pressure lights illuminate.
Centre tank fuel pumps must not be "ON" unless personnel are available in the flight deck to monitor low pressure lights.
This revision may be accomplished by inserting a copy of this Directive into the AFM.
Note: FAA AD 2001-08-24 Amdt 39-12201 refers.
Compliance: Within seven days after the effective date of this Directive.
This Airworthiness Directive becomes effective on 10 May 2001.
Background: On 3 March 2001, a Boeing Model 737-400 series airplane caught fire and burned while parked at a bay at the Don Muang International Airport, Bangkok, Thailand. Although the accident investigation is ongoing and the probable cause of the accident has not been identified, the Government of Thailand, in conjunction with the United States National Transportation Safety Board, has determined that the centre tank exploded shortly after the main fuel tanks of the airplane were refuelled. It appears that the centre tank fuel pumps were operating dry (no fuel passing through them) at the time of the explosion.
This accident is similar to a 1990 centre tank explosion on a Boeing Model 737-300 airplane. The ignition source of that explosion was never identified. The centre tank fuel pumps were operating dry at the time of that explosion.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Extended dry operation of the centre tank fuel pumps, which occurred prior to both incidents, is contrary to the manufacturer’s procedures for safe operation of the fuel pumps. Extended dry pump operation can result in overheating and excessive wear of the pump bearings and consequent contact between rotating and nonrotating parts of the pumps. Both overheating of the bearings and contact between rotating and nonrotating parts have the potential to create an ignition source in the form of hot surfaces or sparks. In addition, during dry operation of the pumps, ignition of vapour in a fuel pump can create a flame front that can reach the fuel tank and cause a fuel tank explosion.
This Directive is issued to prevent ignition of fuel vapours due to the generation of sparks and a potential ignition source inside the centre tank caused by metal-to-metal contact during dry fuel pump operation, which could result in a fire or explosion of the fuel tank. This Directive requires revising the AFM to prohibit extended dry operation of the centre tank fuel pumps.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 27 April 2001
The above AD is notified in the Commonwealth of Australia Gazette on 9 May 2001.
Overview
The Civil Aviation Regulations 1998 (CAR 1998) were enacted to ensure the safety of civil aviation in Australia. They provide a comprehensive framework governing the operation and maintenance of aircraft within Australian airspace. This legislation was introduced to address the need for stringent safety regulations in the aviation sector, aiming to prevent accidents and ensure the safety of passengers, crew, and the general public. Enacted by the Commonwealth Parliament, the CAR 1998 was designed to harmonise with international standards and to provide a robust regulatory environment that promotes safety and efficiency in civil aviation. The policy objective of the regulations is to maintain a high standard of airworthiness and operational safety by setting forth detailed requirements for aircraft operations, maintenance, and personnel qualifications.
Scope and Application
The Civil Aviation Regulations 1998, as amended, under Part 39 – 105, mandates the Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) to address specific safety concerns regarding the operation of Boeing 737 series aeroplanes. This directive applies to all aircraft within the Boeing 737 series, targeting the safe operation of the centre fuel tank and its fuel pumps. The directive is necessitated by incidents of fuel tank explosions, which have been linked to the dry operation of centre tank fuel pumps. CASA's directive mandates specific revisions to the Aircraft Flight Manual (AFM) to prevent such incidents, including restrictions on the operation of centre tank fuel pumps to avoid overheating and potential ignition sources that could lead to explosions. The directive requires these changes to be implemented within seven days of its effective date, which was set as 10 May 2001. This AD does not explicitly exclude any aircraft or circumstances but focuses on ensuring compliance through specified operational changes and updates to the AFM, thereby enhancing the overall safety of Boeing 737 operations.
Key Provisions
The Airworthiness Directive (AD) in question, AD/B737/152, applies to all Model 737 series aeroplanes (subregulation 39.1(1)). The main operative sections of this AD outline specific requirements and instructions for ensuring the safe operation of the centre fuel tank fuel pumps on these aircraft. The requirement section (section (a)) specifies that the Limitations Section of the Aircraft Flight Manual (AFM) must be revised to include detailed instructions regarding the operation of the centre tank fuel pumps to prevent overheating and potential fire or explosion. For ground operations, the centre tank fuel pump switches must not be set to "ON" unless the centre tank fuel quantity exceeds 1,000 pounds (453 kilograms), except during defuelling or fuel transfer operations. Additionally, the centre tank fuel pump switches must be turned "OFF" if both centre tank fuel pump low pressure lights illuminate, and the fuel pumps must not be "ON" unless personnel are available in the flight deck to monitor the low pressure lights. This revision can be accomplished by inserting a copy of this Directive into the AFM (section (b)).
The AD imposes several obligations and requirements on the parties and entities it governs. Primarily, operators of Boeing 737 series aeroplanes must ensure that the AFM is updated to include the specified limitations and operational instructions for the centre fuel tank fuel pumps. This includes the prohibition of operating the centre tank fuel pumps "dry" (without fuel passing through them), which can lead to overheating and damage to the pump bearings. The revised AFM must be in place within seven days of the AD's effective date, which is 10 May 2001 (section (c)). Operators must also ensure that all relevant personnel are aware of these new operational procedures and that they are followed during ground operations.
Failure to comply with the requirements set out in this AD can result in significant civil or criminal consequences. Under the Civil Aviation Regulations 1998, non-compliance with an Airworthiness Directive can lead to enforcement actions by the Civil Aviation Safety Authority (CASA). Such actions may include fines, suspension or revocation of aircraft certificates of airworthiness, or other regulatory penalties. Additionally, in cases where non-compliance leads to an accident or incident, operators may face more severe criminal charges, particularly if the non-compliance is found to be a contributing factor to an accident resulting in loss of life or significant damage. The exact penalties for non-compliance can vary based on the specific circumstances and the severity of the breach, but they are designed to ensure that all operators adhere to the safety directives issued by CASA.