AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B747/155 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.
Boeing 747 Series Aeroplanes
AD/B747/155
Amdt 1
Thrust Reverser Pneumatic Drive 7/2002
Applicability: Model 747 SP, SR, -100,-200 and -300 series aeroplanes powered by Pratt & Whitney JT9D series engines (excluding Model JT9D-70 engines).
Requirement: 1: Carry out an operational test of the reversible gearbox pneumatic drive unit (PDU) or the reversing air- motor PDU in accordance with Boeing Alert Service Bulletin (ASB) 747-78A2131, dated 15 September, 1994, to ensure that the unit can restrain the thrust reverser sleeve.
2: Repeat Requirement 1 operational test.
3: (a) If any operational test required by Requirement 1 or 2 cannot be successfully carried out, repair in accordance with Boeing ASB 747-78A2131, dated 15 September, 1994; OR
(b) Operate the aeroplane in accordance with the conditions and limitations of the Minimum Equipment List (MEL), applicable to the registration mark of the aeroplane, provided the MEL only approves dispatch with:
(i) no more than one thrust reverser on the aeroplane inoperative; and
(ii) the thrust reverser is deactivated in accordance with approved maintenance data; AND
(c) If the aeroplane is operated in accordance with Requirement 3(b), repair the effected thrust reverser in accordance with Boeing ASB 747-78A2131, dated 15 September, 1994; AND
(d) Repeat the inspections and tests required by Requirement 1 or 2, as applicable, after repair under Requirement 3(c); AND
(e) Carry out Requirement 3(a) if any inspection or test carried out under Requirement 3(d) was unsuccessful.
Note: FAA AD 95-16-02 Amdt 39-9321 refers.
Boeing 747 Series Aeroplanes
AD/B747/155 Amdt 1 (Continued)
Compliance: For Requirement 1: Prior to issue of a Certificate of Airworthiness.
For Requirement 2: At intervals not exceeding 2000 flight hours. For Requirement 3(a) or (b): Prior to further flight.
For Requirement 3(c): Within 10 days after thrust reverser deactivation in accordance with the provisions of Requirement 3(b).
For Requirement 3(d) and (e): Prior to further flight. This Amendment becomes effective on 11 July 2002.
Background: This Amendment makes no technical changes to the contents of the Directive.
Therefore, no further action is required for aircraft already in compliance with the original Directive. Several operators have reported incidences to the manufacturer of inoperable PDU brakes or stop-pawls after removal for overhaul. The actions specified in this Directive are intended to ensure that the unit can restrain the thrust reverser sleeve to prevent an inadvertent thrust reverser deployment that could lead to an uncontrolled flight condition.
The original issue of this Airworthiness Directive became effective on 9 November 1995.
James Coyne
Delegate of the Civil Aviation Safety Authority 29 May 2002
The above AD is notified in the Commonwealth of Australia Gazette on 19 June 2002.
Overview
The Civil Aviation Safety Authority (CASA) issued Airworthiness Directive (AD) AD/B747/155 Amendment 1, effective 11 July 2002, to address safety concerns associated with the thrust reverser pneumatic drive unit (PDU) on Boeing 747 Series Aeroplanes powered by Pratt & Whitney JT9D series engines. This AD was introduced to mitigate the risk of inoperable PDU brakes or stop-pawls after overhaul, which could lead to an inadvertent thrust reverser deployment and uncontrolled flight conditions. The AD mandates operational tests of the thrust reverser PDU and stipulates repair procedures if tests are unsuccessful, ensuring aircraft remain airworthy and safe for operation. CASA's policy objective is to maintain and enhance the safety of civil aviation through proactive airworthiness measures, as demonstrated by this directive.
Scope and Application
The Airworthiness Directive AD/B747/155 Amdt 1 applies to Model 747 SP, SR, -100, -200 and -300 series aeroplanes powered by Pratt & Whitney JT9D series engines, excluding Model JT9D-70 engines. It mandates specific actions to correct an unsafe condition concerning the thrust reverser pneumatic drive unit. The requirements include carrying out operational tests of the thrust reverser pneumatic drive unit, repairing the unit if the tests cannot be successfully completed, and operating the aeroplane under certain conditions if a repair is not immediately feasible. The directive is issued under subregulation 39.1 (1) of CAR 1998, with compliance deadlines specified for each requirement. The AD was effective from 11 July 2002, and no further action is required for aircraft already in compliance with the original directive issued on 9 November 1995.
Key Provisions
The Airworthiness Directive (AD) AD/B747/155 Amdt 1 outlines specific requirements and compliance timelines for Boeing 747 series aeroplanes powered by Pratt & Whitney JT9D series engines, excluding those with JT9D-70 engines. Section 1 of the AD mandates that an operational test of the reversible gearbox pneumatic drive unit (PDU) or the reversing air-motor PDU must be conducted in accordance with Boeing Alert Service Bulletin (ASB) 747-78A2131, dated 15 September 1994, to ensure the unit can restrain the thrust reverser sleeve. This test must be carried out prior to the issue of a Certificate of Airworthiness (section 1). Section 2 requires that this operational test be repeated at intervals not exceeding 2000 flight hours. If any operational test cannot be successfully completed, section 3(a) requires the unit to be repaired in accordance with Boeing ASB 747-78A2131, dated 15 September 1994. Alternatively, if the aeroplane is operated in compliance with the conditions and limitations of the Minimum Equipment List (MEL), the aeroplane may be flown with no more than one thrust reverser inoperative, provided the reverser is deactivated in accordance with approved maintenance data, as detailed in section 3(b).
Operators of affected aircraft must adhere to these requirements to ensure continued airworthiness. Specifically, section 1 necessitates compliance before a Certificate of Airworthiness is issued, while section 2 demands compliance at intervals not exceeding 2000 flight hours. For sections 3(a) and 3(b), compliance must occur before further flight. Should an aeroplane be operated under section 3(b), the effected thrust reverser must be repaired within 10 days, as stipulated in section 3(c). Finally, inspections and tests required by sections 3(d) and 3(e) must be conducted prior to further flight. Failure to comply with these provisions can result in serious safety implications, including potential inoperable PDU brakes or stop-pawls, which could lead to an uncontrolled flight condition.
Failure to comply with the requirements of this AD can lead to significant consequences. The AD does not explicitly detail specific penalties for non-compliance; however, the overarching regulatory framework under which the AD operates includes potential civil and criminal penalties. Civil penalties can include fines, while criminal penalties may include imprisonment, reflecting the seriousness of non-compliance with airworthiness directives. Operators must ensure adherence to the AD to avoid such consequences, which underscore the importance of maintaining the airworthiness of the aircraft.