COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Eurocopter AS 355 (Twin Ecureuil) Series Helicopters
AD/AS 355/49 Single-Pole Circuit Breakers 3/99
Applicability: Model AS 355 helicopters, versions E, F, F1, F2 and N equipped with the following single-pole circuit breakers manufactured by Crouzet:
Location | Rating | Part Number |
Emergency Flotation Gear Optional Installation | 5 Amp | 84 400 032 |
| 10 Amp | 84 400 034 |
Other Optional Installations | 1 Amp | 84 400 028 |
| 3 Amp | 84 400 031 |
| 7.5 Amp | 84 400 033 |
| 15 Amp | 84 400 035 |
| 20 Amp | 84 400 036 |
Two types of Crouzet circuit breakers may have been delivered under Eurocopter Part Number (P/N) 704A36-6120-XXX (X indicates any digit). These circuit breakers are either P/N 84 400 XXX or SP4696-XX. This Directive is only applicable to P/N 84 400 XXX circuit breakers.
Note 1: The circuit breakers are known to be installed on helicopters delivered between 24 April 1995 and 31 August 1996. The circuit breakers may also be installed on helicopters delivered prior to 24 April 1995 or after 31 August 1996 if circuit breakers have been replaced on optional installations since 24 April 1995 or if an optional installation was fitted between 24 April 1995 and 31 August 1996.
Requirement: 1. Check the functioning of all circuit breakers, listed in the above table, that are fitted to installations listed in paragraph 1D1 of Eurocopter AS 355 Mandatory Service Bulletin (SB) 01.00.44 date code 98-47.
2. Apply the procedures detailed in paragraph 2B of the SB to all the circuit breakers for the remaining installations.
3. Test each circuit breaker held as spares that has a part number listed in this airworthiness directive by applying a torque load and checking the circuit breaker in accordance with the directions given in paragraphs 2B(1) and 2B(2) of the SB.
4. The use of circuit breakers bearing the part numbers listed in this Airworthiness Directive is prohibited.
Note: DCAG AD 98-510-055(A) refers.
Compliance: 1. Within 200 hours time in service but no later than 26 June 1999.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
2. Prior to 1 January 2000.
3. Prior to installation.
4. From 31 December 1999.
This Airworthiness Directive becomes effective on 25 March 1999.
Background: This AD is issued to check for any loss of electrical continuity for single-pole circuit breakers bearing the part numbers listed. During testing by the OEM a loss of electrical continuity was discovered between the terminals of the circuit breaker in the engaged position. This loss was found to be due to deterioration of the circuit breaker operation brought about by excessive torque loading during installation.
Overview
The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, are a comprehensive set of rules governing civil aviation safety. The Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives under Part 39 - 105 aims to address specific safety issues that may arise in aircraft operations. One such directive, AD/AS 355/49, pertains to the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters and specifically targets single-pole circuit breakers manufactured by Crouzet. The directive was introduced to address a problem identified by the original equipment manufacturer (OEM) involving a loss of electrical continuity in certain circuit breakers, which was traced to deterioration caused by excessive torque loading during installation. The policy objective of this directive is to ensure the safe operation of the affected helicopters by enforcing the timely inspection, testing, and replacement of the specified circuit breakers to prevent potential electrical failures.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, issued under the Civil Aviation Safety Authority, pertains to the airworthiness directives for the Eurocopter AS 355 (Twin Ecureuil) Series helicopters, particularly those equipped with certain single-pole circuit breakers manufactured by Crouzet. This directive applies to specific versions of the AS 355 model helicopters and mandates the inspection and testing of circuit breakers installed on these aircraft. The primary focus is on circuit breakers with particular part numbers, which are known to have been delivered between 24 April 1995 and 31 August 1996, but may also apply to helicopters delivered outside this period if the circuit breakers were replaced or new optional installations were added during the specified timeframe. The directive includes specific requirements for checking the functioning of the circuit breakers, applying detailed procedures for testing, and prohibiting the use of certain circuit breakers altogether. Compliance with these directives must be met within specified timeframes, ensuring that the electrical continuity of the circuit breakers is maintained to prevent potential safety hazards.
Key Provisions
The main operative sections of the Civil Aviation Regulations 1998, Part 39 - 105, pertaining to the Airworthiness Directive (AD) for Eurocopter AS 355 (Twin Ecureuil) Series Helicopters (section 39-105), detail specific requirements for ensuring the airworthiness of certain models of these helicopters. Section 39-105 mandates that operators of AS 355 helicopters, versions E, F, F1, F2, and N, equipped with specific single-pole circuit breakers manufactured by Crouzet, must adhere to a series of checks and procedures to ensure the safety and functionality of these components. These checks include verifying the functioning of all listed circuit breakers, applying specific procedures to all circuit breakers, testing spare circuit breakers, and prohibiting the use of circuit breakers bearing certain part numbers. Compliance with these directives is essential to maintaining the airworthiness of the affected helicopters.
The obligations imposed on the parties governed by this Act, primarily helicopter operators and maintenance personnel, include conducting thorough inspections and tests of the specified circuit breakers. Operators must ensure that all checks are completed within specific timeframes: within 200 hours of service but no later than 26 June 1999, before 1 January 2000, before installation of new circuit breakers, and from 31 December 1999 onwards. Additionally, operators are required to adhere to the procedures detailed in the Eurocopter AS 355 Mandatory Service Bulletin (SB) 01.00.44 and to refrain from using circuit breakers with certain part numbers. These obligations are critical for ensuring that the helicopters remain compliant with airworthiness standards and do not pose a safety risk due to electrical failures.
Failure to comply with the provisions outlined in the Airworthiness Directive may result in civil and criminal consequences. Civil Aviation Safety Authority (CASA) may impose penalties on operators who fail to adhere to the requirements, which could include fines or other monetary penalties. Additionally, non-compliance may result in the grounding of the affected helicopters until the necessary checks and repairs are completed. In severe cases, operators may face criminal charges if their negligence leads to safety incidents or accidents. The maximum penalties for such offences are not specified in the text but are determined by CASA based on the severity of the breach and its impact on aviation safety.