COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Cessna 400 Series Aeroplanes
AD/CESSNA 400/88 Horizontal Stabiliser Front Spar
Attachment Bolt Retaining Nuts
2/86 TX
Applicability: Model 425 with S/Nos 425-0002 to 425-0236 and Model 441 with S/Nos 441-0001 to
441-0354.
Requirement: 1. Visually inspect horizontal stabilizer front spar attachment bolt retaining nuts (P/N NAS 1291-8) for cracking.
2. Replace left and right horizontal stabilizer attachment bolt retaining nuts (P/N NAS 1291-8) in accordance with the instructions contained in CESSNA SB No CQB 85-25R1. Replacement parts must be NAS 1291-8 nuts purchased from the Cessna supply division after 22 November 1985.
Compliance: 1. Within 10 hours time in service after 16 January 1986.
2. a. For applicable aircraft manufactured after 1 January 1984 or which have replaced the horizontal stabilizer after 1 January 1984 or which have replaced the front spar attachment bolt retaining nuts after 1 January 1984, within 10 hours time in service after 16 January 1986.
2. b. For all other applicable aircraft, within 100 hours time in service after
16 January 1986 or at the next scheduled inspection for Maintenance Release issue after 16 January 1986 whichever is the later.
Background: The manufacturer reports that one or both of the horizontal stabilizer front spar attachment bolt retaining nuts may be broken or subject to failure due to hydrogen embrittlement.
Overview
The Civil Aviation Regulations 1998 (Cth), specifically Part 39 - 105, include an Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) to address a safety issue identified with the Cessna 400 series aeroplanes. The AD, identified as AD/CESSNA 400/88, was introduced to rectify a potential problem where the horizontal stabiliser front spar attachment bolt retaining nuts could be prone to cracking due to hydrogen embrittlement, which could compromise the structural integrity of the aircraft. The AD applies to Model 425 aircraft with serial numbers between 425-0002 and 425-0236, and Model 441 aircraft with serial numbers between 441-0001 and 441-0354. The policy objective of this directive is to ensure the ongoing airworthiness and safety of the specified aircraft by mandating inspections and replacements of the affected nuts within prescribed time frames after the directive’s issuance on 16 January 1986.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, apply to certain aircraft models within the Cessna 400 Series, namely the Model 425 with serial numbers 425-0002 to 425-0236 and Model 441 with serial numbers 441-0001 to 441-0354. These regulations mandate specific actions regarding the horizontal stabilizer front spar attachment bolt retaining nuts. The requirement is to visually inspect these nuts for signs of cracking and replace them if necessary in accordance with Cessna Service Bulletin No CQB 85-25R1. The replacement nuts must be of the NAS 1291-8 type, procured from the Cessna supply division after 22 November 1985. Compliance with these directives must be achieved within 10 hours of time in service following 16 January 1986 for some aircraft, while others must comply within 100 hours of time in service or at the next scheduled inspection, whichever is later. These regulations are integral to ensuring the airworthiness and safety of the specified aircraft, addressing the identified risk of hydrogen embrittlement in the attachment nuts.
Key Provisions
The Civil Aviation Regulations 1998, under Part 39 - 105, specify particular safety directives for certain aircraft types, including Cessna 400 Series aeroplanes. In this instance, the legislation targets the Cessna 425 and 441 models with specific serial numbers, mandating inspections and replacements of the horizontal stabilizer front spar attachment bolt retaining nuts (section 2). The requirement is to visually inspect these nuts for signs of cracking, and if necessary, replace them using instructions provided in CESSNA Service Bulletin No CQB 85-25R1, ensuring that replacement parts are NAS 1291-8 nuts sourced from the Cessna supply division post 22 November 1985.
The Act imposes specific obligations on the aircraft operators and maintenance personnel. For applicable aircraft manufactured or having had the horizontal stabilizer replaced after 1 January 1984, compliance must be achieved within 10 hours of service following 16 January 1986 (section 3). For other applicable aircraft, compliance must be achieved within 100 hours of service after 16 January 1986 or at the next scheduled inspection for Maintenance Release, whichever comes later (section 4). This ensures that all aircraft within the specified serial numbers undergo necessary inspections and repairs to address potential safety issues.
Failure to comply with the directives outlined in the legislation may result in significant consequences. While the specific civil or criminal penalties are not detailed in the legislative instrument, non-compliance with Civil Aviation Regulations generally can lead to enforcement actions by the Civil Aviation Safety Authority (CASA). This may include fines, suspension or revocation of aircraft operating certificates, and potential criminal charges for serious breaches that could endanger safety. The exact penalties would depend on the severity and impact of the non-compliance, but the overarching aim is to ensure that all safety directives are strictly followed to maintain the highest standards of aviation safety.