AD/HS 748/3 - Aileron Cable Pulley Guard

Overview

The Civil Aviation Regulations 1998 (Cth) were enacted to ensure the safe operation of civil aircraft within Australia. The Regulations were developed under the authority of the Parliament of Australia, with a policy objective to maintain a high standard of safety in the aviation sector. One of the specific aims of Part 39 - 105, concerning Airworthiness Directives, is to address identified safety issues through the implementation of mandatory modifications or inspections on certain aircraft types. The Airworthiness Directive AD/HS 748/3 pertains to British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes and specifically addresses the installation of aileron cable pulley guards. This directive was introduced to mitigate the risk of aileron cable fouling, which was identified following an incident where an under-tensioned aileron cable turnbuckle fouled a lightening hole in the wing structure, potentially compromising the integrity of the aircraft.

Scope and Application

The Civil Aviation Regulations 1998, specifically under Part 39 - 105 and the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes that do not have Mod 5244 incorporated. This legislation mandates that these aircraft must adhere to certain safety requirements to ensure continued airworthiness. The directive, AD/HS 748/3, pertains to the installation of aileron cable pulley guards, and requires compliance with Jetstream Aircraft Service Bulletin HS748-27-70 Rev 2. This action is in response to a previous incident in which the aileron cable turnbuckle of an under-tensioned cable fouled a lightening hole in the wing trailing edge structure. The directive stipulates that this modification must be completed prior to 1 May 1995. The requirement is aligned with the UK Civil Aviation Authority's AD 009-05-94, which also mandates the installation of rubbing strips at the rear spar adjacent to the aileron cable loop turnbuckles. This legislation applies at a national level across Australia, ensuring uniform safety standards and compliance for the specified aircraft models. The scope of this directive is limited to the specified models of the British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes, and any exclusions or exemptions are not explicitly mentioned in the text.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39, Section 105, outlines a schedule of airworthiness directives for various aircraft types, including the British Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes (section 105). The directive in question, AD/HS 748/3, pertains to the installation of an aileron cable pulley guard. This requirement is applicable to the HS748 aircraft models that do not have Mod 5244 incorporated (section 105.020). The directive mandates that the action must be taken in accordance with the Jetstream Aircraft Service Bulletin HS748-27-70 Rev 2, which provides the technical specifications and procedures for the modification (section 105.030). It is important to note that this directive aligns with the UK Civil Aviation Authority (CAA) AD 009-05-94 (section 105.040). The obligations imposed by this airworthiness directive are clear and specific. Operators of the HS748 Series Aeroplanes without Mod 5244 must ensure that the modification outlined in the Jetstream Aircraft Service Bulletin is completed. This involves the installation of rubbing strips at the rear spar adjacent to where the aileron cable loop turnbuckles are located (section 105.050). The purpose of this modification is to prevent an incident where the turnbuckle of an under-tensioned aileron cable could foul a lightening hole in the wing trailing edge structure, which was the case in a prior incident (section 105.060). Compliance with this directive must be achieved prior to 1 May 1995 (section 105.070). Failure to adhere to the requirements of this airworthiness directive can lead to serious consequences. While specific offences and penalties are not detailed within the text of this directive, breaches of airworthiness directives generally fall under the broader regulatory framework of the Civil Aviation Act 1988. Infractions can result in civil or criminal penalties, depending on the severity and intent behind the breach. The maximum penalties for non-compliance with airworthiness directives can include substantial fines and, in severe cases, imprisonment. The exact penalties would be determined by the Civil Aviation Safety Authority (CASA) and could vary based on the specific circumstances of the breach.