COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
British Aerospace BAe 146 Series Aeroplanes
AD/BAe 146/43 N2 Limitations for Anti-Ice Selection - Placard 5/92
Applicability: All BAe146 series aeroplanes specified in the Requirement Document.
Requirement: Action in accordance with British Aerospace Mandatory Service Bulletin # SB.11-97- 01285A.
Compliance: Prior to 31 September 1992.
Background: There have been incidents of engine N1/N2 mismatch resulting in engine roll back which cannot be restored within TGT limits when operating above FL250 with engine Anti-Ice on and after selecting airframe Anti-Ice on. In addition to introducing a placard giving a flight level and RPM limitation, wiring changes are introduced to inhibit the thrust lever actuated airbrake auto-retract function to enable the airbrake to be operated at high altitude to assist in descent when the thrust levers are forward in compliance with the placard requirements.
Overview
The Civil Aviation Regulations 1998, specifically within Part 39, outlines the safety directives for various aircraft, including the British Aerospace BAe 146 series aeroplanes. One such directive, AD/BAe 146/43, addresses limitations for anti-ice selection by mandating the implementation of placards as per British Aerospace Mandatory Service Bulletin # SB.11-97- 01285A. This directive was enacted to mitigate the risk of engine N1/N2 mismatches, which can lead to engine rollback and compromised thrust recovery above FL250 when both engine and airframe anti-ice systems are active. The directive was introduced by the Civil Aviation Safety Authority to ensure compliance with flight level and RPM limitations, thus enhancing the safety and operational integrity of BAe 146 series aeroplanes. The policy objective is to prevent incidents related to anti-ice system misuse and to provide clear operational guidance to flight crews.
Scope and Application
The Civil Aviation Regulations 1998, as detailed in Part 39 - 105 of the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, applies specifically to all British Aerospace BAe 146 series aeroplanes as outlined in the Requirement Document. This regulation mandates compliance with British Aerospace Mandatory Service Bulletin # SB.11-97- 01285A, which addresses incidents of engine N1/N2 mismatch leading to engine rollback, a condition that cannot be restored within TGT limits when operating above FL250 with engine Anti-Ice on and after selecting airframe Anti-Ice on. The directive aims to enhance safety by introducing a placard specifying flight level and RPM limitations and implementing wiring changes to inhibit the thrust lever actuated airbrake auto-retract function. This allows for airbrake operation at high altitudes to assist in descent when thrust levers are forward, in compliance with the specified placard requirements. The regulation extends to all relevant BAe 146 series aeroplanes within the Commonwealth of Australia, ensuring adherence to these safety measures to mitigate the risks associated with the identified issues.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates certain requirements for the British Aerospace BAe 146 Series Aeroplanes through the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives (AD). One such directive, AD/BAe 146/43, pertains to N2 Limitations for Anti-Ice Selection and Placard. This directive applies to all BAe146 series aeroplanes as specified in the Requirement Document (Section 5/92). The directive requires operators to follow the instructions provided in British Aerospace Mandatory Service Bulletin # SB.11-97-01285A. Compliance with these requirements must be achieved before 31 September 1992.
The primary obligation under this directive is for operators to implement the measures outlined in the referenced service bulletin. This includes installing a placard that provides flight level and RPM limitations, and making necessary wiring changes to inhibit the thrust lever actuated airbrake auto-retract function. These measures are designed to address incidents where engine N1/N2 mismatch has resulted in engine rollback, a condition that cannot be restored within the allowable temperature limits when operating above flight level 250 with engine Anti-Ice on and after selecting airframe Anti-Ice on. By following these requirements, operators can mitigate the risk of engine rollback and ensure safe operation of the aircraft.
Failure to comply with the provisions of the AD/BAe 146/43 directive may result in significant consequences. The Civil Aviation Regulations 1998 outline various offences and penalties for non-compliance with airworthiness directives. In particular, non-compliance with an airworthiness directive may result in the imposition of fines and other civil penalties. Additionally, continued operation of an aircraft in a non-compliant state may result in criminal charges against the operator or relevant personnel. The maximum penalties for such offences can be substantial, reflecting the importance of adhering to airworthiness directives for the safety of the aircraft and its occupants.
In summary, the AD/BAe 146/43 directive requires operators of BAe146 series aeroplanes to implement specific measures to address incidents of engine N1/N2 mismatch and engine rollback. These measures include the installation of a placard and wiring changes to inhibit the thrust lever actuated airbrake auto-retract function. Failure to comply with this directive may result in civil penalties, including fines, and criminal charges, highlighting the critical importance of adherence to airworthiness directives for the safety of the aircraft and its occupants.