Overview

The Civil Aviation Regulations 1998 (CAR 1998), enacted in 1998, were established to regulate civil aviation safety in Australia, addressing the need for comprehensive and up-to-date safety standards. This legislation was enacted by the Australian Parliament to ensure the safe operation of aircraft within Australian airspace. One of the key gaps it aimed to fill was the lack of specific and enforceable safety directives for various aircraft types, which was addressed through the issuance of Airworthiness Directives (ADs) by the Civil Aviation Safety Authority (CASA). The policy objective of these regulations is to ensure the highest standards of safety and reliability in civil aviation through detailed and enforceable directives. This legislative instrument includes an Airworthiness Directive issued by CASA to address the safety issue of potential in-flight oxygen deprivation for Gates Learjet 35 and 36 series aeroplanes. The directive mandates specific emergency procedures to be incorporated into the Aircraft Flight Manual (AFM) to prevent incapacitation of the flight crew due to oxygen deficiency. The AD, issued on 16 January 2001, requires that the AFM Emergency Procedures Section be amended to include specific actions for when the cabin altitude warning horn activates or the cabin altitude exceeds 10,000 feet. This directive was introduced to ensure the safety of the flight crew and maintain control of the aircraft during such emergencies.

Scope and Application

The Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 applies to all Model 35, 35A, 36, and 36A series aeroplanes. The directive mandates an amendment to the Aircraft Flight Manual (AFM), specifically the Emergency Procedures section, to address potential issues that may lead to the incapacitation of the flight crew due to lack of oxygen. The requirement entails revising the title of the existing “Emergency Descent” section to “CABIN ALTITUDE WARNING HORN ACTIVATES OR CABIN ALTITUDE EXCEEDS 10,000 FEET (EMERGENCY DESCENT)”, and inserting the instruction “Don Oxygen Masks and Select 100% Oxygen” immediately following the revised title. Compliance with this directive must be achieved before 24 January 2001, with the directive itself becoming effective on 19 January 2001. This directive is part of the broader regulatory framework managed by CASA and is applicable across the Commonwealth of Australia, ensuring a standardised approach to air safety.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, which pertains to the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, includes an Airworthiness Directive (AD) concerning the Gates Learjet 35 and 36 series aeroplanes. This AD (AD/LEARJET 35/37) was issued to address a safety concern related to the emergency procedures in the Aircraft Flight Manual (AFM) (section 3/2001TX). The AD mandates amendments to the AFM for all Model 35, 35A, 36, and 36A series aeroplanes to update the emergency procedures. The primary requirement (section 3/2001TX) of this AD is to revise the title of the existing "Emergency Descent" section in the AFM to "Cabin Altitude Warning Horn Activates or Cabin Altitude Exceeds 10,000 Feet (Emergency Descent)" and to insert a directive to "Don Oxygen Masks and Select 100% Oxygen" immediately following the revised title. This amendment is intended to ensure that flight crews take appropriate action in an emergency situation to prevent incapacitation due to lack of oxygen. The AD allows the amendment to be accomplished by inserting a copy of the directive into the AFM. The AD imposes obligations on the operators of the affected aircraft to ensure compliance with the specified timeframe. Specifically, the changes to the AFM must be completed before 24 January 2001. Failure to comply with the AD could result in the aeroplane being considered unairworthy, which could lead to significant operational disruptions and potential safety risks. The AD became effective on 19 January 2001, as notified in the Commonwealth of Australia Gazette on the same date. There are no specific offences, penalties, or civil/criminal consequences outlined in the AD for non-compliance with the requirements. However, any failure to comply with the AD could result in enforcement actions by CASA, including grounding of the aircraft until the required changes are made. Such enforcement actions could have significant operational and financial implications for the aircraft operators.