AD/CESSNA 170/55 - Exhaust Heater/Muffler

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, are pivotal in maintaining safety standards within Australia's civil aviation sector. Specifically, Part 39 - 105 addresses Airworthiness Directives, which are critical in ensuring the safety of aircraft operations by mandating compliance with specific maintenance and operational requirements. One such directive, AD/CESSNA 170/55, pertains to the exhaust heater/muffler of certain Cessna 172 Series Aeroplanes, aiming to prevent cracking that could lead to dangerous carbon monoxide levels, thereby safeguarding the safety of passengers and crew. The policy objective behind these regulations is to mitigate risks associated with aircraft maintenance and to ensure the highest standards of airworthiness are maintained throughout Australia's civil aviation operations.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, governs the airworthiness of aircraft within the Commonwealth of Australia, and this includes detailed directives for maintaining the safety of specific aircraft models. For instance, AD/CESSNA 170/55 pertains to the exhaust heater/muffler of certain Cessna 172 Series aeroplanes, particularly those with serial numbers ranging from 36216 through 36769 that have not undergone modification with Cessna Service kit SK-172-10 or SK-172-10A. The regulation requires these aircraft to be inspected and rectified in accordance with FAA AD 90-06-03 R1, which references earlier Cessna Service Letters to provide comprehensive guidance on this issue. The directive mandates compliance within 100 hours of time-in-service from 13 June 1991, aiming to prevent potential cracking of the exhaust heater/muffler that could lead to hazardous carbon monoxide levels. The regulation applies nationally, ensuring consistent safety standards across all jurisdictions within Australia.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, contain the Airworthiness Directives issued by the Civil Aviation Safety Authority (CASA). One such directive, AD/CESSNA 170/55, pertains to the Cessna 170, 172, F172, FR172, and 175 series aeroplanes. This directive is focused on the exhaust heater/muffler of certain Cessna 172 series aircraft (sections 39-105 and AD/CESSNA 170/55). The directive applies to all Cessna 172 series aircraft with serial numbers between 36216 and 36769, provided they have not been modified with the specific Cessna Service kits SK-172-10 or SK-172-10A. According to the directive, the applicable aircraft must undergo an inspection and/or rectification of the exhaust heater/muffler in accordance with FAA AD 90-06-03 R1. The FAA AD references relevant Cessna Service Letters (SL) 170/172-11 and SL 170/172-13, which provide additional information pertinent to this directive. The compliance deadline is set within 100 hours of time-in-service from 13 June 1991. The directive aims to prevent potential cracking of the exhaust heater/muffler, which could lead to hazardous carbon monoxide levels. The Civil Aviation Safety Authority imposes several obligations on the parties governed by this directive. Aircraft owners, operators, and maintenance personnel must ensure that the specified Cessna 170, 172, F172, FR172, and 175 series aeroplanes are inspected and, if necessary, rectified as per the FAA AD 90-06-03 R1. This requirement extends to ensuring that the exhaust heater/muffler is in compliance with the directive within the stipulated timeframe. Failure to adhere to the directive may result in serious safety hazards, as the potential cracking of the exhaust heater/muffler could lead to dangerous carbon monoxide levels. Non-compliance with the AD/CESSNA 170/55 directive could result in significant consequences. While the regulations do not explicitly outline specific offences or penalties in the provided text, non-compliance with CASA directives generally could lead to enforcement actions, including fines and potential grounding of the aircraft. The severity of the consequences depends on the extent of non-compliance and the risk posed to aviation safety. The potential for dangerous carbon monoxide levels underscores the importance of adhering to this directive to ensure the safety of all individuals involved in the operation of these aircraft.