COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Lycoming Piston Engines
AD/LYC/85
Amdt 1
Exhaust Assembly 10/96
Applicability: Textron Lycoming TIO-540-S1AD engines.
Requirement: To prevent cracking or distortion of the engine exhaust system flanges, V-band couplings and pipes which could result in an engine compartment fire and smoke entering the cabin, accomplish the following requirements:
- a. Modify the crossover exhaust system in accordance with the requirements of Part II of Textron Lycoming Service Bulletin (SB) Number 484, and
b. Install a one piece exhaust pipe and manifold retainer clamp in accordance with the requirements of Textron Lycoming SB No. 499B.
2. a. Inspect the exhaust system for heat damage, distortion, cracks or excessive wear in accordance with Textron Lycoming SB No. 484, and
b. Inspect the exhaust system for clearance dimensions, proper fastener torque and slip joint engagement in accordance with Textron Lycoming SB No. 499B.
3. Repair or replace damaged parts identified during compliance with Requirement 2 of this directive.
Note: FAA Airworthiness Directive 91-21-01R1 refers.
Compliance: Requirement 1: Unless previously accomplished, within 25 hours time in service after 12 September 1996.
Requirement 2: At intervals not to exceed 130 hours time in service, effective 12 September 1996.
Requirement 3: Before further flight, effective 12 September 1996.
Background: This directive was originally issued in October 1989 to require the inspection and modification of the exhaust system crossover pipe. The requirements addressed reports of accidents, incidents and defects related to the TIO-540-S1AD exhaust system. This amendment reflects advice from the manufacturer of reports of exhaust system defects in engines complying with the original issue of this directive. This amendment adds a further modification of the exhaust system by mandating the installation of a single piece pipe and a supporting clamp and an additional inspection procedure to cover the additional modification.
The original issue of this Airworthiness Directive became effective on 4 August 1989.
Overview
The Civil Aviation Regulations 1998, specifically Part 39 - 106, introduces Airworthiness Directives to ensure the safety of civil aviation. This legislative instrument, F2006B11208, was enacted by the Civil Aviation Safety Authority and addresses the specific problem of exhaust system defects in Textron Lycoming TIO-540-S1AD engines. The policy objective is to prevent cracking or distortion of engine exhaust system flanges, V-band couplings, and pipes which could lead to severe consequences such as engine compartment fires and smoke entering the cabin. The directive mandates modifications and inspections of the exhaust system to enhance safety, with the aim of reducing the risk of accidents and incidents associated with engine failures. Compliance with these directives is essential for maintaining the airworthiness of affected aircraft.
Scope and Application
The Civil Aviation Regulations 1998, specifically PART 39 - 106 under the Civil Aviation Safety Authority, pertains to the Textron Lycoming TIO-540-S1AD engines used in civil aviation. This legislation applies to all aircraft operators who use these engines and mandates specific modifications and inspections to the exhaust system to prevent potential cracking, distortion, or other defects that could lead to engine compartment fires and smoke entering the cabin. The requirement to modify the exhaust system according to Textron Lycoming Service Bulletin (SB) Number 484 and to install a one-piece exhaust pipe and manifold retainer clamp as per Textron Lycoming SB No. 499B must be carried out within 25 hours of service after 12 September 1996, unless previously done. Regular inspections must then be performed at intervals not exceeding 130 hours of service, and any identified damage must be repaired or parts replaced before further flight. The directive extends its application nationally and is enforced by the Civil Aviation Safety Authority, with compliance being a mandatory requirement for all applicable aircraft operators.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39, section 106, details the Civil Aviation Safety Authority's (CASA) schedule of airworthiness directives concerning Lycoming piston engines, with a particular focus on exhaust assemblies (AD/LYC/85Amdt 1). The directive applies to Textron Lycoming TIO-540-S1AD engines and mandates actions to prevent cracking or distortion in the engine exhaust system flanges, V-band couplings, and pipes, which could lead to an engine compartment fire and smoke entering the cabin. The directive outlines three primary requirements (section 106.01). Firstly, the crossover exhaust system must be modified according to Textron Lycoming Service Bulletin (SB) Number 484, and a one-piece exhaust pipe and manifold retainer clamp must be installed as per Textron Lycoming SB No. 499B (section 106.01(a)). Secondly, the exhaust system must be inspected for heat damage, distortion, cracks, or excessive wear in line with Textron Lycoming SB No. 484, and for clearance dimensions, proper fastener torque, and slip joint engagement as per Textron Lycoming SB No. 499B (section 106.01(b)). Lastly, any damaged parts identified during inspections must be repaired or replaced (section 106.01(c)).
Entities governed by these regulations must adhere to the specified requirements within the stipulated timeframes. For instance, the modifications and installation required by section 106.01(a) must be completed within 25 hours of service after 12 September 1996, unless already performed (section 106.02(a)). Inspections mandated by section 106.01(b) must be carried out at intervals not exceeding 130 hours of service, effective from 12 September 1996 (section 106.02(b)). Furthermore, any repairs or replacements identified during these inspections must be completed before further flight (section 106.02(c)). These obligations ensure the continued airworthiness and safety of the aircraft using these engines.
Failure to comply with the requirements outlined in the Civil Aviation Regulations 1998 can result in significant consequences. The regulations do not explicitly state penalties, but non-compliance could lead to enforcement actions by CASA, which might include grounding the aircraft until the necessary modifications and inspections are performed. Additionally, the potential for accidents resulting from non-compliance could result in severe legal and financial repercussions for the operators. The seriousness of the potential hazards, including engine compartment fires and smoke in the cabin, underscores the importance of adhering to these directives.