AD/HU 269/89 - Droop Stop Nut

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, address the maintenance and safety of aircraft through various Airworthiness Directives. One such directive, AD/HU 269/89, pertains to the Schweizer (Hughes) 269 Series Helicopters and mandates a thorough inspection of the droop stop nut (P/N 269A1340) to ensure it is free from cracks. This was enacted to mitigate the risk of cracking and subsequent failure of the droop stop nut, which could compromise the safety of the aircraft. The directive was issued by the Civil Aviation Safety Authority in response to reports from the manufacturer highlighting the potential for such failures. The policy objective is to ensure the ongoing airworthiness and safety of all Model 269 series helicopters by enforcing regular inspections and timely corrective actions.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to all Schweizer (Hughes) 269 Series Helicopters. This legislative instrument mandates certain inspections and actions to ensure the airworthiness of these helicopters, particularly addressing the potential issue of cracking in the droop stop nut. The directive requires operators to conduct a visual inspection of the droop stop nut (P/N 269A1340) for any indications of cracking, as outlined in Part I of Schweizer Service Information Notice No. N-213, and subsequently perform a dye penetrant inspection for cracking in accordance with Part II of the same notice. Compliance with these requirements must be achieved through specific timelines: the visual inspection must be carried out at each Daily Inspection after 17 December 1987 until the dye penetrant inspection is completed, while the dye penetrant inspection must be completed within 100 hours of time in service after 31 December 1987 or before 31 March 1988, whichever comes first. Additionally, the directive applies to any droop stop nuts held in spares inventory as of 29 September 1987, necessitating a pre-installation inspection. This legislative instrument, therefore, is geographically applicable across the Commonwealth of Australia, ensuring that all operators of Schweizer (Hughes) 269 Series Helicopters adhere to these safety measures to mitigate the risk of cracking and failure of the droop stop nut.

Key Provisions

The Civil Aviation Regulations 1998, specifically under PART 39 - 105, outline the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives (AD) for Schweizer (Hughes) 269 Series Helicopters. This particular AD, AD/HU 269/89, focuses on the droop stop nut (P/N 269A1340). The directive applies to all Model 269 series helicopters, and it mandates two key requirements. Firstly, a visual inspection of the droop stop nut must be conducted to check for any signs of cracking, in accordance with Part I of Schweizer Service Information Notice No. N-213 (Section 1). Secondly, a dye penetrant inspection must be carried out to detect any cracking, following the guidelines set out in Part II of the same notice (Section 1). Compliance with these directives is crucial and follows a specific timeline. According to the regulations, a visual inspection must be performed not later than each Daily Inspection after 17 December 1987, until the dye penetrant inspection is completed (Section 2a). The dye penetrant inspection, however, must be completed within 100 hours of time in service after 31 December 1987 or before 31 March 1988, whichever comes first (Section 2b). Additionally, the inspection must be performed before the installation of any droop stop nuts that were in the spares inventory as of 29 September 1987 (Section 2c). In cases where the pilot in command performs the visual inspection, the precise AD reference must be included in the certification made on the Maintenance Release at the time of the Daily Inspection. Failure to comply with these ADs can result in serious consequences. The regulations are designed to ensure the safety of the aircraft and its occupants, and non-compliance can lead to significant penalties. While the specific penalties are not detailed in the provided text, it is understood that breaches of Civil Aviation Regulations can result in both civil and criminal penalties, including fines and imprisonment. These penalties are intended to enforce adherence to the safety standards set by CASA.