AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/HS 748/31 and issues the following AD under subregulation 39.1 (1) of CASR 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.
British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes
AD/HS 748/31
Amdt 1
Gust Lock Baulking Actuator 1/2004
Applicability: All HS748 aeroplanes.
Requirement: 1. Modify the aeroplane’s gust lock system (Modification No 7673) in accordance with Parts 1 and 2 of BAe Systems Service Bulletin (SB) HS748-27-135 Revision 1 dated 10 December 2002.
2. Conduct an inspection of the baulk lever in accordance with Appendix 2 of SB HS748-27-135 Revision 1 or Revision 2 dated 2 October 2003.
3. Rework the Requirement 1 modification to the gust lock system in accordance with SB HS748-27-135 Revision 2.
Note 1: CAA(UK) AD 003-12-2002 refers.
Compliance: For Requirement 1 - Remains unchanged as ‘Before 1 September 2003’.
For Requirement 2 - Remains unchanged as ‘Initially within 750 hours time in service (TIS) or 240 days, whichever occurs first, after the installation of the baulking actuator and thereafter, repeat the inspection at intervals of 750 hours TIS or 240 days, whichever occurs first’.
Note 2: 750 hours TIS or 240 days is the ‘C’ Check interval.
For Requirement 3 - Before 29 February 2004.
This Amendment becomes effective on 22 January 2004.
Background: BAe advises that there have been two incidents where re-engagement of the elevator gust-lock may have caused a flying control restriction. The original issue of this Directive required the installation of a rotary actuator at the elevator gust lock that will baulk the mechanism after gust-lock withdrawal so that an uncommanded re- engagement cannot occur.
This Amendment revises the wiring of the gust lock actuator to ensure correct operation.
British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes
AD/HS 748/31 Amdt 1 (continued)
The original issue of this Airworthiness Directive became effective on 20 March 2003.
Jim Coyne
Delegate of the Civil Aviation Safety Authority 4 December 2003
The above AD is notified in the Commonwealth of Australia Gazette on 24 December 2003.
Overview
The Civil Aviation Safety Authority Act 1998, enacted by the Australian Parliament, governs the regulation of civil aviation safety in Australia. The Act empowers the Civil Aviation Safety Authority (CASA) to issue Airworthiness Directives to address identified safety issues in aircraft. One such Airworthiness Directive, AD/HS 748/31, was initially issued on 20 March 2003 to address a safety concern regarding the gust lock system of British Aerospace (Hawker Siddeley) HS 748 Series aeroplanes. This concern involved potential uncommanded re-engagement of the elevator gust lock, which could cause flying control restrictions. The policy objective of this directive is to ensure that the identified safety issue is rectified to maintain the airworthiness of the affected aircraft.
Scope and Application
The Airworthiness Directive (AD) AD/HS 748/31, as amended by AD/HS 748/31 Amdt 1, applies specifically to all British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes within the Commonwealth of Australia. This AD mandates the modification of the aeroplane's gust lock system to address safety concerns related to the potential for uncommanded re-engagement of the elevator gust-lock, which could lead to flying control restrictions. The AD is issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998 (CASR 1998) by the Civil Aviation Safety Authority (CASA) delegate. The directive requires modifications to the gust lock system (Modification No 7673) as per the BAe Systems Service Bulletin (SB) HS748-27-135 Revision 1 and Revision 2, and inspections of the baulk lever as per the same bulletin. Compliance with the AD involves completing the specified modifications and inspections within certain timeframes, such as before 1 September 2003 for the initial modification and within 750 hours of time in service or 240 days, whichever comes first, for subsequent inspections. This AD is effective as of its notification in the Commonwealth of Australia Gazette on 24 December 2003.
Key Provisions
This Airworthiness Directive (AD) (AD/HS 748/31 Amdt 1), issued by the Civil Aviation Safety Authority (CASA) delegate, outlines specific modifications and inspections required for British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes to address safety concerns. The primary requirements (sections 1 to 3) mandate modifications to the aeroplane’s gust lock system, inspections of the baulk lever, and rework of the modifications according to specified service bulletins. These actions are designed to correct the unsafe condition identified and ensure the aircraft remains airworthy. The directive applies to all HS 748 aeroplanes, and compliance must be achieved within specified timeframes and conditions as detailed in the directive.
The AD imposes clear obligations on the operators and maintenance personnel of HS 748 aeroplanes. Operators must ensure that the modifications outlined in Requirement 1 are completed before 1 September 2003, and the inspections specified in Requirement 2 are conducted initially within 750 hours of time in service (TIS) or 240 days after the installation of the baulking actuator, and then repeated at intervals of 750 hours TIS or 240 days. Requirement 3 mandates that the rework of the modification be completed before 29 February 2004. These obligations are essential to maintain the aircraft’s airworthiness and comply with safety regulations.
Failure to comply with the requirements set out in this AD may result in serious safety risks and potential legal consequences. While the AD does not explicitly state penalties for non-compliance, CASA may impose fines, administrative actions, or other enforcement measures under the Civil Aviation Act 1988 and the Civil Aviation Regulations 1988. Non-compliance could also lead to grounding of the aircraft, which could incur significant operational and financial costs for the operator. Ensuring adherence to the AD is critical to maintaining the safety and airworthiness of HS 748 aeroplanes.