Overview

The Airworthiness Directive (AD) for the Learjet 45 series aeroplanes, issued in 2002 by the Civil Aviation Safety Authority (CASA), addresses safety concerns associated with the anti-ice manifold assembly. The AD mandates specific revisions and inspections to mitigate the risk of system failure that could lead to the blocking of anti-ice system ducts, thereby degrading the aeroplane's anti-ice capacity. This was particularly pertinent in icing conditions where the aeroplane was previously allowed to operate. The policy objective behind this AD was to ensure that the Learjet 45 series aeroplanes remained airworthy by prohibiting flight into icing conditions until the necessary inspections and replacements were completed. The directive was enacted to ensure compliance with safety standards and to prevent potential hazards during flight operations.

Scope and Application

This Airworthiness Directive, issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998, applies to specific Learjet 45 series aeroplanes identified by serial numbers in Bombardier (Learjet) Service Bulletin A45-30-2, excluding those that have already incorporated the requirements of Section 2 Accomplishment Instructions of the same service bulletin. The directive mandates certain actions to address an unsafe condition relating to the anti-ice system, specifically the potential for the splitter within the anti-ice manifold to fail, leading to blockage of the anti-ice system ducts and degradation of the anti-ice capacity of the aeroplane. The actions required include revising the limitations section of the FAA approved Aircraft Flight Manual to prohibit flight into icing conditions, inspecting and replacing the anti-ice manifold assembly, and amending the Learjet Model 45 Maintenance Manual. Compliance with these requirements must be achieved within 25 hours Time in Service from the effective date of the directive, which is 13 June 2002. The directive applies nationally, as it is issued by the Civil Aviation Safety Authority, a Commonwealth authority.

Key Provisions

The Airworthiness Directive AD/LJ45/3 issued under the Civil Aviation Regulations 1998, specifically under subregulation 39.1(1), mandates certain actions to address safety concerns associated with Learjet 45 series aeroplanes. This AD applies to Learjet 45 series aeroplanes listed by serial number in Bombardier (Learjet) Service Bulletin A45-30-2, excluding those that have already incorporated the requirements of Section 2 Accomplishment Instructions in the same bulletin. The key provisions require a revision of the limitations section in the FAA-approved Aircraft Flight Manual (AFM) to explicitly state that flight into icing conditions is prohibited (section 1). Additionally, the directive mandates an inspection and potential replacement of the anti-ice manifold assembly as outlined in Bombardier (Learjet) SB A45-30-02 (sections 2 and 3). Furthermore, the Learjet Model 45 Maintenance Manual must be amended to reflect the details in Temporary Revisions 4-2, 5-2, and 30-1 dated 2 January 2001 (section 4). Compliance with these requirements must be achieved within 25 hours of Time in Service (TIS) from the effective date of the AD, which is 13 June 2002. This Airworthiness Directive imposes several obligations on the operators and maintainers of the affected Learjet 45 series aeroplanes. Primarily, these include updating the limitations section of the Aircraft Flight Manual to adhere to the specified wording regarding flight in icing conditions and performing an inspection of the anti-ice manifold assembly. If any issues are found during inspection, the assembly must be replaced as per the detailed instructions in Bombardier (Learjet) SB A45-30-02. Additionally, the Maintenance Manual must be revised to include the changes specified in the aforementioned temporary revisions. These actions are essential to mitigate the risk of the anti-ice system being compromised, thereby ensuring the safety of the aircraft when operating in conditions that could lead to icing. Failure to comply with the requirements of this Airworthiness Directive can result in serious safety risks. The AD highlights that operating the Learjet 45 series aeroplanes in icing conditions without the mandated modifications could lead to the degradation of anti-ice capacity, increasing the likelihood of hazardous flight conditions. While the specific penalties for non-compliance are not detailed in the text, under the Civil Aviation Regulations 1998, non-compliance with an Airworthiness Directive can lead to severe civil and criminal consequences. These may include fines, the grounding of the aircraft, and potential legal action against the operators or maintainers found in breach of the directive. The exact penalties would depend on the specific circumstances and the severity of the non-compliance, as well as any resulting safety incidents.