AD/LEARJET 35/33 - Outflow/Safety Valve

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, address safety concerns related to aircraft airworthiness through various Airworthiness Directives (AD). One such AD is AD/LEARJET 35/33, which pertains to the Gates Learjet 35 and 36 Series Aeroplanes. Enacted by the Civil Aviation Safety Authority (CASA), this directive was introduced to address the risk of rapid decompression due to potential fracture or cracking of the outflow/safety valve poppet. The problem this legislation aims to mitigate involves safety hazards associated with the outflow/safety valve in the specified aircraft models, which could potentially lead to catastrophic outcomes. The policy objective is to ensure the safe operation of these aircraft by mandating specific amendments to the aircraft flight manual and other procedural requirements. Compliance with AD/LEARJET 35/33 is mandatory and includes revising the Aircraft Flight Manual to update the maximum operating altitude, applying specific service bulletins, and ensuring the removal of certain flight manual changes once new measures are implemented. The directive sets specific timelines for compliance, aiming to enhance the safety and reliability of the affected aircraft by addressing the identified risk of valve failure.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to the Gates Learjet 35 and 36 series aeroplanes, as identified in Learjet Service Bulletin SB 35/36-21-19. This legislative instrument is concerned with ensuring the airworthiness of these aircraft models by addressing a specific issue with the outflow/safety valve. The regulations mandate certain actions to be taken to ensure the aircraft's safe operation, including amending the Aircraft Flight Manual to adjust the maximum operating altitude and making specific changes to the outflow/safety valve as detailed in the Learjet Service Bulletin. Compliance with these directives is mandatory and must be adhered to by the relevant operators and maintenance personnel of the affected aircraft. The geographic scope of this legislation is national, applying across Australia and overseen by the Civil Aviation Safety Authority (CASA). There are no stated exclusions or exemptions within this directive, and compliance is required for all applicable aircraft within the specified timeframes. Subordinate instruments may further detail the implementation and enforcement of these airworthiness directives.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes an Airworthiness Directive (AD) for Gates Learjet 35 and 36 Series Aeroplanes, outlined in AD/LEARJET 35/33. This AD mandates changes to ensure the safety of these aircraft models. Firstly, operators must revise the Aircraft Flight Manual to adjust the maximum operating altitude to 41,000 feet (section 1). This can be done either by inserting a CASA 'green page' amendment issued under approval number "A/35-A36/6" or by inserting Learjet Temporary Flight Manual Change 94-15 dated 9 January 1995 (section 1(a) and (b)). Secondly, operators must follow the procedures outlined in paragraphs 2B and 2C of Learjet Service Bulletin 35/36-21-19 dated 3 January 1995 (section 2). Once these actions are completed, the flight manual change introduced in section 1 must be removed by applying to the CASA District Airworthiness Office responsible for the aircraft (section 3). Operators of Learjet 35/36 series aircraft must ensure compliance with these requirements by adhering to specified timelines. Compliance with Requirement 1, which involves amending the Aircraft Flight Manual, must be achieved prior to 1 April 1996 (section Compliance Requirement 1). For Requirement 2, which involves the procedures from the Learjet Service Bulletin, compliance must be achieved prior to 28 February 1997 (section Compliance Requirement 2). Requirement 3, which involves the removal of the flight manual change, must occur after the completion of Requirement 2 (section Compliance Requirement 3). Failure to comply with the AD may result in significant legal and safety consequences. The Civil Aviation Regulations 1998 enforce strict penalties for non-compliance with airworthiness directives. Breaches of these regulations can lead to enforcement actions, which may include fines, suspension or revocation of air operator certificates, and potential criminal charges for individuals responsible for non-compliance. The maximum penalties can vary but may include substantial fines and imprisonment, reflecting the critical nature of ensuring aircraft airworthiness and safety.