AD/CESSNA 185/13 Amdt 1 - Pneumatic Stall Warning System

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA) under the authority of the Australian Parliament, establish comprehensive safety standards and regulations to ensure the safety and efficiency of civil aviation in Australia. One specific legislative instrument, F2006B05103, introduced an amendment to the Cessna 185 Series Aeroplanes through AD/CESSNA 185/13 Amendment 1, focusing on the pneumatic stall warning system. This amendment was introduced to address potential safety issues arising from the operation of the pneumatic stall warning system in certain Cessna 185 models, specifically those without the specified horn reed assembly and protective screens. The policy objective behind this amendment is to ensure that the stall warning system functions correctly, thereby enhancing flight safety by providing pilots with clear and reliable stall warnings. This legislative instrument mandates a pre-flight check of the pneumatic stall warning system and the installation of a specific placard to remind pilots to test the system. Additionally, it outlines modifications that can be made to comply with the safety directive. The requirement for a pre-flight test must be carried out before each flight, while the placard must be installed within 25 hours of time in service after 3 September 1968. The amendment also provides a means to remove these requirements if the specified modifications are implemented, ensuring that the aircraft meets the necessary safety standards.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the safety standards and directives concerning aircraft, including the Cessna 185 series aeroplanes. This regulation applies to all models of Cessna 185 series aeroplanes equipped with pneumatic stall warning systems that do not include the horn reed assembly P/N 0413483-2, P/N 0713348-1 or subsequent, and protective screens over the horn bell and stall warning system opening on the left wing. The geographic reach of these regulations is national, enforcing compliance across the Commonwealth of Australia as per civil aviation safety standards. The regulation mandates that operators check the pneumatic stall warning system's correct operation by applying slight suction at the stall warning opening in the left wing, ensuring a clearly audible sound. Additionally, a placard must be installed in full view of the pilot to remind them to pre-flight test the pneumatic stall warning system. These requirements may be met by incorporating specified modifications to the stall warning reed assembly and protective screens, followed by flight testing to ensure the stall warning horn operates effectively. The compliance timelines require pre-flight checks before each flight and placard installation within 25 hours of time in service after 3 September 1968.

Key Provisions

The Civil Aviation Regulations 1998, particularly in Part 39 - 105, establish the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, which includes AD/CESSNA 185/13, Amendment 1, concerning the pneumatic stall warning system for Cessna 185 Series aeroplanes. The regulation applies to all models equipped with a pneumatic stall warning system that does not incorporate specific horn reed assemblies (P/N 0413483-2, P/N 0713348-1 or subsequent) and protective screens over the horn bell and stall warning system opening on the left wing (Section 1). The directive mandates that operators check the system's correct operation by applying slight suction at the stall warning opening in the left wing, ensuring the horn produces a clearly audible sound (Section 1). This check can be performed and certified by the pilot, as referenced in the Cessna 100 Series Service Manual from 1963 to 1967, Section 16. Additionally, a placard must be installed in full view of the pilot stating "PRE-FLIGHT TEST THE PNEUMATIC STALL WARNING SYSTEM" (Section 2). Operators of the affected Cessna 185 Series aeroplanes are required to adhere to several obligations under this directive. Before each flight, the pneumatic stall warning system must be checked for correct operation (Section 1). This involves applying slight suction at the stall warning opening and ensuring the horn produces a clearly audible sound, with the possibility of covering the opening with a clean piece of cloth first (Section 1). Furthermore, a placard must be installed within 25 hours time in service after 3 September 1968, stating "PRE-FLIGHT TEST THE PNEUMATIC STALL WARNING SYSTEM" in full view of the pilot (Section 2). These requirements ensure that the stall warning system is functional and that the pilot is properly informed about the necessity to test the system pre-flight. Failure to comply with the provisions of this airworthiness directive can result in serious safety implications and potential legal consequences. Specifically, if the operator does not perform the required checks on the pneumatic stall warning system before each flight or fails to install the prescribed placard within the specified timeframe, they may be in breach of the regulation. The consequences of such non-compliance could potentially lead to grounding of the aircraft until the required modifications or checks are completed. Although specific penalties are not detailed in this directive, general regulatory breaches under the Civil Aviation Act 1988 can result in significant civil or criminal penalties, including fines and imprisonment, depending on the severity of the breach and its impact on aviation safety.