AD/CESSNA 185/44 - Instrument Panel Light Dimming Rheostat

Overview

The Civil Aviation Safety Authority (CASA) introduced the Civil Aviation Regulations 1998, which were enacted to ensure the safety of civil aviation in Australia. Part 39 - 105 of the Regulations includes the Schedule of Airworthiness Directives, which mandates specific actions to address safety issues in aircraft. One such directive, AD/CESSNA 185/44, pertains to the Cessna 185 Series aeroplanes and specifically addresses the issue of instrument panel light dimming rheostats. This directive was introduced in response to a reported inflight fire caused by a short in the electrical wiring controlled by the instrument panel light dimming rheostat in a Cessna Model 172, as notified by the Federal Aviation Administration (FAA). The policy objective is to replace the existing rheostat with an improved version that is both current-limiting and heat-protected, thereby reducing the risk of inflight fires due to defective rheostats. Compliance with this directive is required before 3 October 1994.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the Civil Aviation Safety Authority’s schedule of airworthiness directives, focusing on ensuring the safety and airworthiness of aircraft. This particular directive, AD/CESSNA 185/44, applies to the Cessna Model 185D, 185E, and 185F aircraft, specifically those with serial numbers ranging from 185-0777 through 185-02310. The requirement is that these aircraft must replace their existing instrument panel light dimming rheostat with an improved version, as outlined in the Accomplishment Instructions of Cessna Single Engine Service Bulletin SEB92-33 Revision 2 dated 10 September 1993. This directive was necessitated by a reported inflight fire in a Cessna Model 172, which was traced to a short in the electrical wiring controlled by the instrument panel light dimming rheostat. The replacement ensures that the new rheostat is both current-limiting and heat-protected, thereby reducing the risk of an inflight fire. Compliance with this directive is mandatory, with the requirement to complete the replacement before 3 October 1994.

Key Provisions

The main operative sections of the Civil Aviation Regulations 1998, specifically AD/CESSNA 185/44, detail the requirement for the replacement of the instrument panel light dimming rheostat in certain Cessna 185 series aeroplanes. According to section (3/94), the directive applies to Cessna Model 185D, 185E, and 185F aircraft with serial numbers ranging from 185-0777 through 185-02310 inclusive. The requirement outlined in this section mandates that unless the replacement has already been carried out, the existing instrument panel light dimming rheostat must be replaced. Some installations may also necessitate the fitting of a doubler, as per the Accomplishment Instructions of Cessna Single Engine Service Bulletin SEB92-33 Revision 2 dated 10 September 1993. This directive is in response to a report of an in-flight fire caused by a short in the electrical wiring controlled by the instrument panel light dimming rheostat, as detailed in FAA AD 93-24-15 Amdt 39-8764. The Civil Aviation Regulations 1998 impose specific obligations and requirements on the parties governed by AD/CESSNA 185/44. Operators of the specified Cessna 185 series aircraft must ensure that the replacement of the instrument panel light dimming rheostat is completed as per the given specifications and instructions. This involves adherence to the Accomplishment Instructions of Cessna Single Engine Service Bulletin SEB92-33 Revision 2, which provides detailed guidance on the replacement process. Furthermore, operators are required to verify that the rheostat replacement has been carried out before the compliance deadline of 3 October 1994, as stated in the compliance section of the directive. In the event of non-compliance with AD/CESSNA 185/44, there are potential civil and criminal consequences. While the specific penalties are not detailed in the directive, non-compliance with Civil Aviation Regulations can generally result in significant penalties. These may include fines, enforcement actions, and potential legal proceedings against the operators or entities responsible for the non-compliance. The severity of the penalties can vary depending on the nature and extent of the breach, but the overarching objective is to ensure that all applicable safety directives are strictly adhered to, thereby maintaining the highest standards of aviation safety.