AD/CESSNA 188/22 - Wing Front and Rear Spar

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the safety of civil aviation through the issuance of airworthiness directives. Enacted by the Australian Government, these regulations are administered by the Civil Aviation Safety Authority (CASA). The directive AD/CESSNA 188/22, issued in 1974, targets a critical safety concern related to the structural integrity of the wing spars in Cessna 188 (Agwagon) Series aeroplanes. The policy objective is to mitigate the risk of in-flight structural failure by mandating regular inspections for cracks in specific areas of the aircraft's wing spars. By doing so, CASA ensures that these vintage aircraft continue to meet the necessary safety standards, thus protecting the aviation community and the general public. The directive applies to all Cessna 188 models produced before 1972, with serial numbers ranging from 188-0001 to 188-00832. It stipulates that inspections must be conducted at specified intervals based on the aircraft's modification status, using a magnifying glass or an equivalent device to detect potential cracks. Compliance with these inspection requirements is essential to ensure the continued airworthiness of these aircraft, thereby maintaining the high safety standards expected in civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, as detailed in Part 39 - 105, specifically target the Cessna 188 (Agwagon) Series Aeroplanes, applying to all models prior to the 1972 Agwagon model with serial numbers ranging from 188-0001 to 188-00832. This regulation mandates that the Civil Aviation Safety Authority (CASA) oversee the inspection of these aircraft to ensure compliance with safety standards. The inspections must focus on identifying cracks in critical areas such as the front spar at the splice area near the strut pick-up, the front spar at the fuselage attachment area, and the rear spar at the fuselage attachment area. Additionally, there is a requirement to inspect the upper flange of the rear spar channel at the outer end of the attachment fitting. The inspections must be conducted using a magnifying glass of at least 4X magnification or an alternative device such as a “Syte Ade.” The frequency of these inspections varies based on the aircraft's modification status, with unmodified aircraft requiring inspections at intervals not exceeding 100 hours of time in service, modified aircraft adhering to a 150-hour interval, and those with specific modifications or service kits requiring inspections at intervals not exceeding 500 hours, post 31 May 1974.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 105, include specific directives concerning the airworthiness of Cessna 188 (Agwagon) Series aeroplanes, particularly focusing on structural integrity in the AD/CESSNA 188/22 directive issued on 5 July 1974. This directive mandates inspections for cracks in critical areas of the aircraft’s wing spars. Specifically, Section 1 of the directive requires inspections for cracks in the front spar at the splice area near the strut pick-up, the front spar at the fuselage attachment area, and the rear spar at the fuselage attachment area. Additionally, it requires inspecting the upper flange of the rear spar channel at the outer end of the attachment fitting. The inspections must be conducted using a magnifying glass of at least 4X magnification or an alternative device such as a “Syte Ade”. Compliance with these inspection requirements is crucial and varies based on the aircraft’s modifications and service history. For unmodified aircraft, inspections must be carried out at intervals not exceeding 100 hours of time in service. For aircraft modified to Rex Drawing No. RA491, Issue 4, the interval extends to 150 hours of time in service. Furthermore, for aircraft with a doubler P/N 1620058.1 installed or a service kit specified in SL No. SE 74-4, the inspection interval can be extended to 500 hours of time in service, provided the inspections commence after 31 May 1974. These intervals ensure that potential structural issues are identified and addressed in a timely manner. The obligations imposed by this directive are stringent and aim to maintain the airworthiness and safety of the aircraft. Operators and maintenance personnel must adhere to the specified inspection intervals and use the recommended inspection methods to ensure that any cracks or defects are detected. Failure to comply with these requirements can lead to significant safety risks, including the potential for in-flight structural failure. Non-compliance with the airworthiness directives can result in serious consequences, including penalties and legal action. While the specific penalties are not detailed in this directive, non-compliance with Civil Aviation Regulations can generally lead to enforcement actions by the Civil Aviation Safety Authority (CASA), including fines, suspension or revocation of airworthiness certificates, and potential criminal charges in cases of gross negligence or willful disregard of safety regulations. These consequences underscore the importance of strict adherence to the inspection and maintenance schedules outlined in the directive.