AD/DHC-8/49 - Inspection of Wiring Harness

Overview

The Civil Aviation Regulations 1998, enacted by the Australian Government, govern various aspects of civil aviation within the country, including safety standards and airworthiness directives. One such directive, AD/DHC-8/49, addresses specific concerns with Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes, particularly the DHC-8 series 100, 200, and 300 within certain serial number ranges. This directive was introduced to mitigate the risk of electrical wiring chafing behind the lavatory, which had previously led to incidents of severe local overheat and smoke within the aircraft. The policy objective of this directive is to ensure the safety of passengers and crew by implementing specific modifications to inspect and protect the wiring harness, as detailed in deHavilland Service Bulletin 8-24-50 dated 25 April 1997. This measure ensures compliance with international safety standards and helps prevent potential hazards associated with wiring damage.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes an airworthiness directive concerning Bombardier (Boeing Canada/De Havilland) DHC-8 Series aeroplanes. This directive applies to specific de Havilland Inc. DHC-8 aircraft series 100, 200 and 300, with serial numbers ranging from 003 to 433 inclusive, excluding aircraft with serial numbers 031, 408, and 413. The directive mandates the installation of deHavilland Modification 8/2624, which entails a special inspection for chafing of the cable harness behind the lavatory and the removal of the lavatory forward panel, as detailed in deHavilland Service Bulletin 8-24-50 dated 25 April 1997. Compliance with this directive is required unless the specified modifications were already completed by 9 July 1998. The airworthiness directive became effective on 9 October 1997 and aims to address reported instances of electrical wiring chafing, which has led to severe local overheating and smoke within the cockpit and cabin.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives for Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes, with AD/DHC-8/49 pertaining to the inspection of the wiring harness. This directive (section 1) applies to de Havilland Inc. DHC-8 aircraft, series 100, 200, and 300, with serial numbers ranging from 003 to 433, excluding 031, 408, and 413. The primary requirement (section 2) is the installation of deHavilland Modification 8/2624, which includes a special inspection for chafing of the cable harness behind the lavatory and the cutaway of the lavatory forward panel. This modification must be carried out in accordance with deHavilland Service Bulletin 8-24-50 dated 25 April 1997. The directive (section 3) imposes obligations on aircraft operators to ensure that the specified modifications are completed. Operators must adhere to the deHavilland Service Bulletin 8-24-50 and install the required modifications to mitigate the risk of electrical wiring chafing, which can cause severe local overheating and smoke in the cockpit and cabin. Compliance with this directive is mandatory unless the modifications were already performed before 9 July 1998. The directive came into effect on 9 October 1997, as stated in section 4. In terms of consequences for non-compliance (section 5), the regulations do not explicitly state penalties within this specific directive, but non-compliance with CASA airworthiness directives generally carries significant risks. Failure to comply with these directives can result in severe civil and criminal penalties under the Civil Aviation Act 1988. Civil penalties may include substantial fines, and criminal penalties can include imprisonment, reflecting the critical nature of maintaining airworthiness standards to ensure the safety of all passengers and crew.