AD/DHC-6/52 - Windscreen Washer/De-Icing System - Discontinued Use of Isopropyl Alcohol

Overview

The Civil Aviation Regulations 1998, amended by the Legislative Instrument F2006B09141, were enacted to address the problem of potential in-flight fires caused by the use of isopropyl alcohol in the windscreen washer/de-icing system of DHC-6 (Twin Otter) series aeroplanes. This legislation was introduced to ensure the safety of air operations by prohibiting the use of isopropyl alcohol in these systems and requiring the use of approved fluids only. The policy objective is to mitigate the risk of fire by discontinuing the use of potentially hazardous substances and ensuring that only approved substances are used in the specified aircraft systems. Enacted by the Australian Parliament, this regulation applies to all DHC-6 aircraft with windscreen washer/de-icing systems that use isopropyl alcohol and mandates the immediate cessation of its use to prevent any future incidents.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, apply to all DHC-6 aircraft that incorporate a windscreen washer/de-icing system utilising isopropyl alcohol. This directive is issued by the Civil Aviation Safety Authority (CASA) and mandates the cessation of using a 50/50 mixture or 100 percent isopropyl alcohol in the windscreen washer/de-icing system. Instead, only proprietary fluids specified in De Havilland of Canada Service Bulletin 6/422 or otherwise approved by the Department of Aviation are permitted. Additionally, any labels indicating the use of isopropyl alcohol for filling the windscreen washer/de-icing system reservoir must be removed. This regulation is effective immediately and is grounded in safety concerns following an incident where an in-flight fire was potentially caused by isopropyl alcohol escaping into the flight compartment area due to a faulty connection. The directive is applicable across the Commonwealth of Australia, encompassing all relevant aircraft and operators within the national jurisdiction.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates that all DHC-6 (Twin Otter) series aeroplanes that have a windscreen washer/de-icing system must comply with Airworthiness Directive AD/DHC-6/52 (Section 10/82). This directive requires the immediate cessation of using 50/50 mixture or 100 percent isopropyl alcohol in the windscreen washer/de-icing system. Instead, operators must use only proprietary type fluids such as those detailed in De Havilland of Canada Service Bulletin 6/422, or as otherwise approved by the Department of Aviation. Additionally, any labels on the aircraft that indicate filling requirements for isopropyl alcohol must be removed from the area above the windscreen washer/de-icing system reservoir. The obligations imposed by these regulations include ensuring that all operators of affected DHC-6 aircraft take the necessary steps to transition to the approved fluid types and remove any outdated labels from the aircraft. This involves conducting a thorough inspection of the aircraft’s windscreen washer/de-icing system, ensuring that the correct fluids are available for use, and verifying that any labels directing the use of isopropyl alcohol have been properly removed. Operators must also ensure that their maintenance and operational procedures are updated to reflect these changes, and that all personnel involved in the operation and maintenance of the aircraft are informed of the new requirements. Failure to comply with these directives can result in serious consequences. While the specific penalties for non-compliance are not detailed in the provided text, it is known that breaches of Civil Aviation Regulations can lead to enforcement actions, which may include fines, suspension of airworthiness certificates, or even criminal charges in cases of gross negligence. The exact penalties would depend on the severity of the breach and the discretion of the Civil Aviation Safety Authority (CASA) in enforcing the regulations. It is crucial for operators to adhere to these directives to ensure the continued airworthiness and safety of their aircraft.