AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/EC 120/3 Amdt 3 and issues the following AD under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Eurocopter EC 120 Series Helicopters
AD/EC 120/3
Amdt 4
Reinforced Coupling Tube Assembly 9/2004
Applicability: All Eurocopter EC 120B helicopters fitted with engine-to-main gearbox (MGB) coupling tube Part Number (P/N) C631A1101101 and/or fitted with the engine mount comprising the parts detailed in paragraph 1.A. of Eurocopter EC 120 Alert Service Bulletin (ASB) No. 04A005.
Requirement: 1. EC120B helicopters not incorporating an engine mount block modified in accordance with Eurocopter EC120 ASB No. 71.003 AND prior to serial number 1170 AND not incorporating Eurocopter EC120 Service Bulletin (SB) No.
71.005:
- Perform a visual inspection of the engine to MGB coupling tube in accordance with Paragraph 2.B of Eurocopter EC120 ASB No. 05A003; and
b. Remove from service, MGB coupling tube P/N C631A1101101 assemblies found to be cracked; and
c. Remove from service, MGB coupling tube P/N C631A1101101 assemblies.
2. EC120B helicopters prior to serial number 1170 and not incorporating an engine mount modified in accordance with Eurocopter EC120 SB No. 71.003:
- Remove from service, engine mount components detailed in Paragraph 1.A of Eurocopter EC120 ASB No. 04A005.
3. EC120B helicopters serial number 1170 and higher and EC120B helicopters incorporating an engine mount modified in accordance with Eurocopter EC120 SB No. 71.003, but not modified in accordance with Eurocopter EC120 SB No. 71.005:
- Perform a visual inspection of the engine to MGB coupling tube in accordance with Paragraph 2.B of Eurocopter ASB 05A003; and
b. Remove from service, MGB coupling tube P/N C631A1101101 assemblies found to be cracked; and
c. Remove from service, MGB coupling tube P/N C631A1101101 assemblies.
4. EC120B helicopters all serial numbers which have modified in accordance with Eurocopter EC120 SB No. 71.005:
- Remove from service, MGB coupling tube P/N C631A1101101 assemblies.
5. For MGB coupling tube P/N C631A1101101 assemblies held as spares:
- Perform a dye penetrant inspection of the MGB coupling tube in accordance with paragraph 2.B of Eurocopter SB 71.005.
The inspection detailed in Requirement 1 (a) and Requirement 3 (a) of this directive may be carried out and certified by the pilot provided the pilot has completed an approved training program.
Note : DGAC Airworthiness Directive F-2003-325 R1 refers.
Compliance: Requirement 1.
- Unless previously accomplished, prior to further flight; and thereafter at intervals not to exceed 5 flight hours from last inspection or following the last flight of the day, whichever occurs first.
b. Before further flight.
c. Prior to exceeding 1,000 hours time in service (TIS) for the MGB coupling tube.
Requirement 2.
a. Remains unchanged as detailed in Amendment 3 of this Directive, prior to 30 June 2004.
Requirement 3.
- Unless previously accomplished, within 25 flight hours from the effective date of this directive and thereafter at intervals not to exceed 25 flight hours.
b. Before further flight.
c. Prior to exceeding 20,000 hours TIS for the MGB coupling tube. Requirement 4.
a. Prior to exceeding 20,000 hours TIS for the MGB coupling tube.
Requirement 5:
a. Before fitment to a helicopter modified in accordance with Eurocopter EC120 SB No. 71.005 and where the coupling tube was previously fitted to a helicopter not modified in accordance with Eurocopter EC120 SB No. 71.005.
This Amendment becomes effective on 2 September 2004.
Background: This Directive was originally issued to address a report of cracks being found in a reinforced engine to MGB coupling tube assembly. The investigation of that report has determined a certain engine mount configuration may induce excessive loading on the coupling tube. In response, the manufacturer has released an improved engine mount, revised the reinforced coupling tube inspection procedures and revised the life limits for the reinforced coupling tube assembly. This Amendment introduces terminating action of the inspections for helicopters modified by Eurocopter EC120B SB 71.005.
Amendment 3 of this Airworthiness Directive became effective on 25 December 2003 Amendment 2 of this Airworthiness Directive became effective on 16 May 2002.
Amendment 1 of this Airworthiness Directive became effective on 15 November 2000.
The original issue of this Airworthiness Directive became effective on 3 May 2000.
Bernard Malcolm Hole
Delegate of the Civil Aviation Safety Authority 23 July 2004
The above AD is notified in the Commonwealth of Australia Gazette on Gazette Date.
Overview
The Civil Aviation Safety Authority (CASA) issued Airworthiness Directive AD/EC 120/3 Amdt 4 on 2 September 2004 to address safety concerns associated with cracks in the reinforced engine-to-main gearbox (MGB) coupling tube assembly of Eurocopter EC 120B helicopters. This amendment was enacted under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998, revoking the previous amendment, AD/EC 120/3 Amdt 3. The policy objective of this directive is to ensure the airworthiness of Eurocopter EC 120B helicopters by mandating specific inspection and maintenance actions to prevent the in-service use of cracked coupling tube assemblies, thereby mitigating the risk of potential engine failure or other safety hazards. The directive applies to all Eurocopter EC 120B helicopters fitted with certain engine-to-main gearbox coupling tube parts and requires various inspections and actions depending on the helicopter’s serial number and the modifications it has undergone.
Scope and Application
The Airworthiness Directive (AD) AD/EC 120/3 Amdt 4, issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Safety Regulations 1998, pertains specifically to all Eurocopter EC 120B helicopters equipped with a specific engine-to-main gearbox (MGB) coupling tube part number or an engine mount as detailed in certain service bulletins. The AD applies to these aircraft to ensure safety by addressing the risk of cracks in the MGB coupling tube, which can arise due to certain configurations of the engine mount. The directive outlines specific actions that must be taken, such as visual inspections, removal of cracked parts from service, and inspections of spare parts before they are fitted, all of which are to be carried out in accordance with detailed procedures outlined in the Eurocopter service bulletins. Compliance with this AD is mandatory and must be achieved within certain timeframes related to flight hours and time in service for the MGB coupling tube. The AD extends its jurisdictional reach across the Commonwealth of Australia and is enforced through the regulatory powers of CASA. It does not specify any exclusions or exemptions, implying that all applicable helicopters must comply with the directive without exception. The AD may be further detailed or modified through subsequent amendments or subordinate instruments issued by CASA.
Key Provisions
The main operative sections of this Airworthiness Directive (AD) specify the conditions under which specific actions must be taken for Eurocopter EC 120B helicopters to address safety concerns with the engine-to-main gearbox (MGB) coupling tube. Section 1 of the AD mandates a visual inspection of the engine-to-MGB coupling tube for certain helicopters (Section 1(a)) and requires the removal from service of cracked or unmodified coupling tube assemblies (Section 1(b) and 1(c)). Section 2 requires the removal of specific engine mount components for helicopters that meet certain criteria (Section 2). Section 3 sets out further inspections and removal actions for helicopters that meet additional specified conditions (Section 3). Section 4 details the actions to be taken for helicopters modified in accordance with a specific service bulletin (Section 4). Finally, Section 5 sets out the inspection requirements for spare MGB coupling tube assemblies (Section 5).
The AD imposes specific obligations on the operators and maintainers of the Eurocopter EC 120B helicopters. Operators must ensure that their helicopters comply with the AD requirements, including conducting the specified visual inspections, removing defective or unmodified parts, and adhering to the stipulated inspection intervals. For example, Section 1(a) requires a visual inspection before further flight and at intervals not exceeding 5 flight hours or the end of the flight day, whichever comes first. Section 2 mandates that certain engine mount components be removed before 30 June 2004. Section 3 sets out a requirement for inspections before further flight and at intervals not exceeding 25 flight hours or before the coupling tube reaches 20,000 hours of time in service. Section 4 specifies that inspections must occur before the coupling tube reaches 20,000 hours of time in service. Finally, Section 5 requires a dye penetrant inspection of spare coupling tube assemblies before they are fitted to a modified helicopter.
Failure to comply with the requirements of this AD may result in various civil and criminal consequences. The AD does not explicitly state penalties, but non-compliance with airworthiness directives can lead to enforcement actions by the Civil Aviation Safety Authority (CASA), including fines, suspension or revocation of airworthiness certificates, and other regulatory penalties. Pilots who conduct inspections must have completed an approved training program, and failure to do so may also result in enforcement actions. Furthermore, operating an aircraft that does not comply with airworthiness directives could result in additional civil penalties under the Civil Aviation Act 1988 and potentially criminal charges under the Criminal Code Act 1995 if the non-compliance results in an accident or other serious safety incidents.