Overview

The Civil Aviation Regulations 1998, specifically within Part 39, introduced the Civil Aviation Safety Authority Schedule of Airworthiness Directives to ensure the safety of aircraft operations in Australia. One such directive is AD/CESSNA 550/1, which pertains to the inspection and modification of the wing main spar for the Cessna 550 (Citation II) Series Aeroplanes. This legislation was enacted to address the identified problem of fatigue cracks in the wing main spar upper and lower caps at wing station 37, as revealed through full-scale fatigue testing and inspections of high-time Citation aircraft. The policy objective, as stated within the text, is to mandate regular inspections and modifications to prevent structural failure and ensure continued airworthiness, thereby enhancing aviation safety for these aircraft models. The regulations are enforced by the Civil Aviation Safety Authority and are designed to comply with both domestic and international aviation safety standards.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to all Cessna 550 series aeroplanes with serial numbers as referenced in Service Letter No. 550-57-1. This legislation mandates certain inspection and modification requirements for the wing main spar of these aircraft to ensure their continued airworthiness. The geographic reach of this regulation is nationwide, enforced by the Civil Aviation Safety Authority (CASA) under the Commonwealth of Australia. The regulations establish a mandatory inspection and, if necessary, modification protocol for the wing main spar upper and lower caps in the area of wing station 37, referencing specific documents from both Cessna and the Federal Aviation Administration (FAA). Compliance with these directives is critical to maintain the structural integrity of the affected aircraft. The regulations also provide flexibility by allowing modifications to be carried out at any time, potentially exempting the aircraft from further inspections under certain conditions. Additionally, further inspections are required at intervals not exceeding 1200 flight hours or 1200 landings after the initial modification.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, mandates certain actions for Cessna 550 (Citation II) series aeroplanes. For these aircraft, there are three main provisions outlined in AD/CESSNA 550/1 concerning the wing main spar. Firstly, Section 1 requires an inspection of the wing spar upper and lower cap in the area of wing station 37 in accordance with Cessna Service Letter (SL) No. 550-57-1 Rev. 1 dated 1 May 1979, which is referenced by FAA AD 79-12-06. Secondly, Section 2 necessitates an inspection and modification of the wing spar in accordance with Cessna Service Bulletin (SB) No. 550-57-3 Rev. 1 dated 28 March 1980, when any crack detected in the inspection reaches or exceeds 0.30 inches in length. This modification may be performed at any time and exempts the aircraft from further inspections under Section 1. Thirdly, Section 3 requires a visual inspection for further cracks in the wing main spar upper and lower caps of aircraft modified under Section 2 in the area of the WS 37 modification, at or prior to exceeding 1200 hours after modification and thereafter at intervals not exceeding 1200 hours or 1200 landings, whichever occurs first. The obligations imposed by these sections are clear and specific. Operators of Cessna 550 series aeroplanes must comply with the inspection and modification requirements outlined in the relevant Service Letters and Service Bulletins. These obligations include performing the initial inspection as per Section 1, conducting the necessary modifications when specified crack lengths are reached according to Section 2, and ensuring ongoing visual inspections as per Section 3. Failure to adhere to these requirements can lead to serious safety concerns, as the directive addresses fatigue cracks that have been identified in service. In terms of consequences, there are potential penalties and legal ramifications for non-compliance with the AD/CESSNA 550/1 directives. While the specific penalties are not detailed within the text provided, non-compliance with CASA directives generally can result in enforcement actions by CASA. These actions can include civil penalties, enforcement notices, and in severe cases, the grounding of the aircraft. The potential criminal consequences could involve prosecution for breaches that lead to unsafe conditions, with penalties including fines and imprisonment, depending on the severity and impact of the non-compliance.