AD/DHC-8/45 Amdt 1 - Passenger Compartment Lighting Wiring

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes an airworthiness directive addressing safety concerns related to Bombardier (Boeing Canada/De Havilland) DHC-8 Series aeroplanes. This legislation was enacted by the Australian Government to ensure the safety of civil aviation, particularly in relation to the wiring of passenger compartment lighting in certain models of DHC-8 aeroplanes. The problem it addresses is the reported chafing of electrical wiring in the cabin ceiling lighting system, which may lead to shorting, smoke, and fire risks. The policy objective, as indicated, is to mitigate these risks by requiring specific modifications and inspections to protect the wiring. This directive was introduced to align with international safety standards and ensure the reliability and safety of the specified aircraft models in Australian airspace.

Scope and Application

The Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives applies to specific models of Bombardier (Boeing Canada/De Havilland) DHC-8 series aeroplanes, specifically those with serial numbers ranging from 002 through 010, 012 through 201, 203 through 209, 211 through 215, 217 through 220, 222, and 223, excluding certain modifications. This directive mandates that these aircraft must incorporate de Havilland Modification 8/2158, which involves installing Teflon spiral wrap to the wiring of ceiling and sidewall lights in the passenger compartment. Furthermore, the lavatory lighting system wiring must be inspected to determine whether the Teflon spiral wrap has been installed. If not, it must be fitted in accordance with the specified Bombardier service bulletin. Compliance with this directive requires that the actions be completed within 1000 hours of time in service or six calendar months after the effective date of the amendment, whichever is sooner. This directive ensures that the risk of chafing and subsequent shorting of the electrical wiring, which could lead to smoke and fire hazards, is mitigated.

Key Provisions

The Civil Aviation Regulations 1998, under PART 39 - 105, detail the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives. Specifically, AD/DHC-8/45 Amendment 1 pertains to Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes. This directive applies to specific models and serial numbers of DHC-8 aeroplanes, excluding those with certain interior modifications (section 1). The main requirement (section 2) mandates the incorporation of de Havilland Modification 8/2158 for the installation of Teflon spiral wrap to the wiring of ceiling and sidewall lights in the passenger compartment. This must be done in accordance with Bombardier Regional Aircraft Division Dash 8 Service Bulletin 8-33-35 dated 1 September 1995. Additionally, the directive requires an inspection of the lavatory lighting system wiring to ascertain whether the Teflon spiral wrap has been installed. If the wrap is not present, it must be fitted in line with the revised Dash 8 Service Bulletin 8-33-35 revision B dated 25 September 1998. The obligations imposed by this directive on the relevant parties or entities include ensuring the specified modifications and inspections are carried out as per the CASA's requirements. Specifically, operators of the affected DHC-8 aeroplanes must implement the necessary changes to the wiring to prevent electrical chafing, which could lead to fires. Compliance with the directive is mandatory and must be achieved within 1000 hours of time in service or within six calendar months from the effective date of the amendment, whichever comes first (section 3). The compliance deadline is explicitly stated as within 1000 hours of time in service or six calendar months from 29 February 1996 for the original directive, and from 22 April 1999 for the amendment. The directive also references Transport Canada Aviation AD CF-95-18 Rev 1, which highlights the importance of these measures by citing previous reports of electrical chafing in the cabin ceiling lighting system (section 4). The background information reveals that chafing may cause shorting between wires and the aircraft structure, leading to smoke and fire risks. The amendment aims to correct potential misinterpretations of the original directive, ensuring that all necessary wiring protections are installed. Non-compliance with these airworthiness directives could result in severe safety risks and potential legal consequences. Although the specific penalties are not detailed in this directive, breaches of airworthiness requirements generally incur civil penalties under the Civil Aviation Act 1988, which can include fines and potential grounding of the aircraft.