COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Cessna 170, 172, F172, FR172 and 175 Series Aeroplanes
AD/CESSNA 170/19
Amdt 1
Pneumatic Stall Warning System 6/83
Applicability: All models with pneumatic stall warning systems not incorporating 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.
Requirement: 1. Check the pneumatic stall warning system for correct operation by applying a slight suction with the mouth at the stall warning opening in the left wing. A properly functioning horn will provide a sound that is clearly audible. It may be advisable to first cover the opening with a clean piece of cloth. Cessna 100 Series Service Manual 1963 to 1967 Section 16 refers.
Note: This check may be performed and certified by the pilot.
2. Install the following placard in full view of the pilot:
“PRE-FLIGHT TEST THE PNEUMATIC STALL WARNING SYSTEM”.
3. The requirements of paragraphs 1 and 2 may be removed by incorporation of the following modifications. Replace the stall warning reed assembly P/N 0413028-1 with reed assembly P/N 0413483-2, P/N 0713348-1 or subsequent and install an 18 x 14 or 18 x 16 mesh screen over the exposed horn bell inside the cabin and over the left wing opening. Flight test the aircraft to assure the stall warning horn sounds at 5 to 10 knots above the stalling speed.
Compliance: For para. 1 - Before each flight.
For para. 2 - Within 25 hours time in service after 3 September 1968.
Background: This amendment reflects latest Cessna Part Number change.
Overview
The Civil Aviation Regulations 1998, specifically within Part 39 - 105, includes the Civil Aviation Safety Authority Schedule of Airworthiness Directives. This legislation, enacted by the Commonwealth of Australia, was introduced to ensure the ongoing safety of aircraft operations, specifically addressing gaps in the maintenance and operation of older aircraft models. The policy objective is to enhance air safety through the regulation of airworthiness directives, ensuring that aircraft are maintained to a standard that minimises the risk of accidents. The amendment in question, AD/CESSNA 170/19, targets Cessna 170, 172, F172, FR172, and 175 series aeroplanes, focusing on the pneumatic stall warning system. This directive was necessary to address issues with the original design of the stall warning system, which could potentially fail to alert pilots adequately, thereby posing a risk during flight operations. Compliance with these directives is mandatory, with specific checks and modifications required to be conducted before each flight and within a set timeframe post the directive's introduction.
Scope and Application
The Civil Aviation Regulations 1998, under Part 39 - 105, mandate the Civil Aviation Safety Authority's Schedule of Airworthiness Directives for various Cessna aeroplane models, including the Cessna 170, 172, F172, FR172, and 175 series, specifically addressing the pneumatic stall warning system. This regulation applies to all models with pneumatic stall warning systems that do not incorporate the horn reed assembly with part numbers 0413483-2, 0713348-1 or subsequent, and protective screens over the horn bell and stall warning system opening on the left wing. The requirement is for pilots or authorised personnel to check the system's correct operation by applying slight suction at the stall warning opening in the left wing, ensuring the horn provides a clearly audible sound. A placard must also be installed in full view of the pilot stating, "PRE-FLIGHT TEST THE PNEUMATIC STALL WARNING SYSTEM." Additionally, compliance with these requirements must be achieved before each flight for the check, and within 25 hours time in service after 3 September 1968, for the placard installation. Modifications to the stall warning reed assembly and the installation of protective screens can satisfy these requirements.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, outlines the requirements for maintaining the airworthiness of various aircraft, including the Cessna 170, 172, F172, FR172, and 175 series aeroplanes. Within this legislative framework, AD/CESSNA 170/19 Amendment 1 focuses on the pneumatic stall warning system. The applicability of this directive (section 1) is limited to models with a pneumatic stall warning system that does not incorporate specific horn reed assemblies or protective screens.
The requirements (section 2) are straightforward. Firstly, the pneumatic stall warning system must be checked for correct operation by applying slight suction at the stall warning opening in the left wing. This check must be performed before each flight, and it can be done by the pilot. Secondly, a placard reading "PRE-FLIGHT TEST THE PNEUMATIC STALL WARNING SYSTEM" must be installed in full view of the pilot. This placarding requirement must be fulfilled within 25 hours of time in service after 3 September 1968.
The obligations imposed by this amendment (section 3) are primarily on the aircraft owners or operators. They must ensure that the pneumatic stall warning system is correctly operational and that the appropriate placard is installed as specified. Compliance with these directives is mandatory and must be performed before each flight for the operational checks and within the stipulated timeframe for the placard installation.
Failure to comply with the requirements (section 4) may result in various consequences. While the specific civil or criminal penalties are not detailed in the text, it is clear that non-compliance could lead to the aircraft being deemed unairworthy, which could result in grounding and potential enforcement actions by the Civil Aviation Safety Authority. Additionally, pilots operating non-compliant aircraft could face regulatory scrutiny and possible sanctions. The precise penalties would depend on the nature and severity of the non-compliance, as well as any subsequent investigation and findings by the relevant authorities.