AD/CESSNA 150/42 - Battery/Battery Contactor Cable Routing

Overview

The Civil Aviation Regulations 1998, as amended, were enacted to regulate civil aviation safety and operational standards within Australia. The specific legislative instrument F2006B04940, part of the Airworthiness Directives, targets issues identified within the Cessna 150, F150, 152, and F152 series aeroplanes. This directive was introduced to address the problem of potential cable chafing and subsequent failures in aircraft that had undergone modifications to relocate the battery. The policy objective, as indicated, is to enhance the safety of these aircraft by preventing failures of the up elevator cable, which could lead to severe accidents. The Civil Aviation Safety Authority, under the authority of the Parliament of Australia, issued this directive to ensure compliance with safety standards and to mitigate risks associated with battery relocation modifications.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to all Cessna 150, F150, 152 and F152 series aeroplanes that have undergone modifications relocating the battery from the firewall to the aft fuselage or from just aft of the baggage compartment aft bulkhead to any other aft position. This regulation is enforced by the Civil Aviation Safety Authority (CASA) and is applicable across the Commonwealth of Australia, thus encompassing all states and territories. The specified aircraft modifications must comply with the outlined safety directive to prevent the up elevator cable failure, which was the cause of a fatal accident identified in a Cessna 150D. Compliance requires the tie-down of the battery to battery contactor cable to the lock pin attaching the battery box cover to the battery box using prescribed materials to ensure a minimum clearance of one inch from the elevator up cable, along with a visual inspection and repair of any damage to the cables before the next flight. The directive mandates compliance within 25 hours of time in service after 20 August 1988. This regulation does not provide for any exclusions or exemptions and applies uniformly to all specified aircraft models and serial numbers.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes Airworthiness Directive AD/CESSNA 150/42, which focuses on the routing and inspection of battery cables on certain Cessna models. This directive applies to a range of Cessna 150 and F150 series aircraft that have had their batteries relocated from the firewall to the aft fuselage or from just aft of the baggage compartment aft bulkhead to another aft position (s.1). The directive mandates that to prevent potential failure of the up elevator cable, the "battery to battery contactor" cable must be secured using specific tie-down methods to ensure a minimum of one-inch clearance between the battery cable and the elevator up cable (s.2(a)). Additionally, the directive requires a visual inspection of both the battery cable and elevator cable for any signs of damage, with any damage repaired before the next flight (s.2(b)). Compliance with these requirements must be achieved within 25 hours of the aircraft being in service after 20 August 1988 (s.3). The Cessna 150/42 Airworthiness Directive imposes specific obligations on aircraft operators and maintenance personnel. Operators and maintenance personnel must ensure that the battery cables are correctly routed and secured as specified in the directive. This includes the use of approved tie-down materials such as MIL-C-5649 cord, MS17821, or MS3367 tiedown strap. Furthermore, a thorough visual inspection of the battery and elevator cables must be conducted to identify any damage, and any detected damage must be repaired before the next flight. Operators must also keep records of compliance with the directive, including the date and time of compliance, to demonstrate adherence to the regulatory requirements (s.3). Failure to comply with the provisions of the Airworthiness Directive AD/CESSNA 150/42 can result in serious consequences. While the specific penalties for non-compliance with Civil Aviation Regulations are not detailed in this directive, non-compliance can generally lead to enforcement actions by the Civil Aviation Safety Authority (CASA). These actions may include fines, suspension or revocation of the aircraft's certificate of airworthiness, or other administrative penalties. In severe cases, failure to adhere to airworthiness directives can result in criminal charges, especially if the non-compliance is found to have contributed to an accident or incident. The potential penalties for such breaches can be substantial, reflecting the critical importance of maintaining aircraft safety standards (s.3).