COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Cessna 400 Series Aeroplanes
AD/CESSNA 400/103
Amdt 2
Wing Spars Delamination and Corrosion 6/95
Applicability: All models 404 and 441.
Requirement: 1. Gain access to the rear spar from CWS 34.25 to CWS 82.3 Port and Starboard and inspect the full area of the laminated spar web for delamination and/or corrosion, between the specified stations using an NDI method acceptable to the Authority.
Note: Qantas NDT Technique U-53 using a Fokker Bond tester is an acceptable method.
2. Repair any detected corrosion in accordance with a scheme approved pursuant to CAR 35. Where an aircraft has been repaired as a result of inspection in accordance with this issue, or previous issues, of this Directive, inspect in accordance with the requirements of the approved repair scheme.
Compliance: a. Unless already accomplished, within forty five days after 03 August 1994; thereafter at intervals not exceeding one year; or
b. As specified in the approved repair scheme.
Spar web replacement and internal corrosion protection in accordance with a scheme approved pursuant to CAR 35 terminates the repeat inspection requirement.
The date for compliance with the initial issue of this Directive was within 30 days after 8 June 1994, for amendment 1 the effective date was 3 August 1994.
This Amendment is effective from 25 May 1995
Background: An Australian operator found substantial delamination and corrosion necessitating replacement of the rear spar web in a number of aircraft. Due to similar construction techniques, and as a precautionary measure, a one time visual inspection was also required on the front and centre spar webs.
Amendment 1 was raised following advice from the manufacturer, and an Australian major maintenance organisation, as well as the results of inspections in accordance with the initial issue of the Directive, which demonstrated the total unreliability of a tap test in one case, and extensive spar cap corrosion in another.
Amendment 2 is raised following the extensive inspections undertaken as a result of Amendment 1. These have shown that the problem is confined to the rear spar web.
Overview
The Civil Aviation Regulations 1998, amended through F2006B08290, were enacted to address safety concerns related to the delamination and corrosion of wing spars in Cessna 400 Series Aeroplanes. This legislation, administered by the Civil Aviation Safety Authority, aims to ensure that all models 404 and 441 of these aircraft undergo rigorous inspection and maintenance to prevent structural failures. The policy objective is to maintain and enhance the safety standards in civil aviation by mandating specific inspection and repair protocols. Compliance with these directives is essential, requiring inspections within specified timeframes and the use of approved methods such as the Qantas NDT Technique U-53. This legislative instrument was developed in response to findings of substantial delamination and corrosion in Australian-operated Cessna 400 Series aeroplanes, necessitating immediate and ongoing safety measures.
Scope and Application
The Civil Aviation Regulations 1998, as amended, under the Civil Aviation Act 1988, apply to all Cessna 404 and 441 models in Australian airspace. This legislation mandates that operators of these aircraft must conduct inspections for delamination and corrosion of the rear spar web between specified stations using an acceptable non-destructive inspection method. The inspection must occur within forty-five days of 3 August 1994, or as specified in an approved repair scheme, and must be repeated at intervals not exceeding one year. The requirement for these inspections arises from findings of substantial delamination and corrosion in Australian-operated aircraft, prompting a one-time visual inspection of the front and centre spar webs as a precautionary measure. Any detected corrosion must be repaired according to a scheme approved under CAR 35. The replacement of the spar web and the implementation of an internal corrosion protection scheme, approved under CAR 35, will terminate the requirement for repeat inspections. This regulatory framework is enforced by the Civil Aviation Safety Authority and can be extended or modified through subordinate instruments.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, includes AD/CESSNA 400/103 Amendment 2 which pertains to the inspection and maintenance of the rear spars of Cessna 400 series aeroplanes, namely models 404 and 441. This directive mandates that operators must gain access to the rear spar from wing station (CWS) 34.25 to CWS 82.3 on both port and starboard sides and inspect the full area of the laminated spar web for delamination and/or corrosion (AD/CESSNA 400/103 Amendment 2). Inspections must be conducted using a non-destructive inspection (NDI) method approved by the Civil Aviation Safety Authority. The Qantas NDT Technique U-53, which employs a Fokker Bond tester, is recognised as an acceptable inspection method. Any corrosion found must be repaired in accordance with a scheme approved under the Civil Aviation Regulations (CAR 35). If an aircraft has previously undergone repair following inspection under this directive or its amendments, further inspections must be carried out in accordance with the approved repair scheme.
Operators of the Cessna 400 series aeroplanes are obligated to adhere to the specified inspection and repair procedures outlined in AD/CESSNA 400/103 Amendment 2. The initial inspection must be completed within forty-five days after 3 August 1994. Subsequent inspections must occur at intervals not exceeding one year or as stipulated by an approved repair scheme. Once the spar web has been replaced and internal corrosion protection has been implemented in accordance with an approved scheme under CAR 35, the requirement for repeat inspections is terminated. The directive was initially effective within thirty days of 8 June 1994, with Amendment 1 taking effect on 3 August 1994, and Amendment 2 becoming effective from 25 May 1995. These timelines underscore the urgency and ongoing commitment required by operators to maintain the airworthiness of their aircraft.
Failure to comply with the provisions of AD/CESSNA 400/103 Amendment 2 may result in significant consequences. The regulations are enforced to ensure the safety and reliability of aircraft operations. Operators who do not adhere to the inspection and repair requirements may face enforcement actions under the Civil Aviation Act 1988. Such non-compliance can lead to penalties, including fines and potential grounding of the aircraft. The severity of the penalties reflects the critical nature of maintaining the structural integrity of the spar webs, which are vital to the safety of the aircraft and its occupants. The detailed requirements and the strict compliance deadlines underscore the importance of adhering to these safety measures to prevent any potential hazards that could arise from delamination or corrosion of the spar webs.