AD/EC 225/12 Amdt 1 Main Rotor Drive Epicyclic Reduction Gear Module (Cth)
AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/EC 225/12 and issues the following AD under subregulation 39.001(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 225 Series Helicopters
| AD/EC 225/12 Amdt 1 | Main Rotor Drive - Epicyclic Reduction Gear Module | 6/2009 TX |
Applicability: | EC 225 LP model helicopters, all serial numbers. |
Requirement: | 1. Unless already accomplished per the requirements of AD/EC 225/11 (EASA Emergency AD 2009-0087-E) or the original issue of this Directive (EASA Emergency AD 2009-0095-E), remove and inspect the Main Gear Box (MGB) epicyclic reduction gear module in accordance with the instructions of paragraph 2.B.2 of Eurocopter Alert Service Bulletin (ASB) No. 05A017 Revision 2 dated 23 April 2009 or later revision approved by the European Aviation Safety Agency (EASA). |
| 2. Unless already accomplished, modify the MGB epicyclic reduction gear module in accordance with the instructions of paragraph 2.B.3 of ASB No. 05A017 Revision 2. | |
| 3. Each time particles are detected on the electric magnetic plug of the MGB epicyclic reduction gear module follow the applicable maintenance procedures as described in the relevant Aircraft Maintenance Manual. | |
| 4. A MGB may not be installed on any helicopter, unless it has been checked for condition and modified as instructed in ASB No. 05A017 Revision 2. | |
| Later revisions of ASB No. 05A017 Revision 2 approved by the European Aviation Safety Agency (EASA) are acceptable for compliance with this Amendment. | |
| 5. Report to Eurocopter Technical Support (see contact details below) the completion of Requirements 1 and 2 and should particles be found while complying with any Requirement of this Amendment, send the particles to Eurocopter with a report giving details of their location when first discovered. | |
| Eurocopter (STDI) – Aéroport de Marseille Provence | |
| Note: EASA Emergency AD 2009-0099-E dated 23 April 2009 refers. |
Compliance: | For Requirements 1 and 2 - Before further flight after the effective date of this Amendment. |
| For Requirement 3 - Before further flight. | |
| For Requirement 4 - After the effective date of this Amendment. | |
| For Requirement 5 - Within 24 hours of completing Requirement 1, 2 or 3. | |
| This Amendment becomes effective on 24 April 2009. | |
Background: | This Telex Airworthiness Directive is issued following the accident of the AS 332 L2 helicopter registered G-REDL that occurred on 1 April 2009, off the coast of Scotland near Aberdeen. Early investigations showed that a failure within the epicyclic reduction module of the MGB resulted in the rupture of the MGB case, which allowed the main rotor head to separate from the helicopter. In the light of this information, enhancement of the means for detection of MGB contamination was deemed of the utmost importance. As an initial precautionary measure Telex AD/S-PUMA/84 was issued with that aim. Additionally, the original issue of this Directive was issued to require a one-time inspection for absence of particles in the MGB epicyclic reduction gear module on the entire fleet. |
| While the investigation is still in progress with the aim of determining as soon as possible the sequence of the failure(s) and initiating cause(s), this Amendment, which retains the main requirements of the both the original issue of this Directive and AD/S-PUMA/84, requires the modification of the chip collector inside the MGB - located between the epicyclic module and the main module - to enhance the early detection capability of the magnetic plugs of the gearbox sump and the epicyclic module. With that aim, this Amendment requires removing the magnetic elements installed on the chip collector, together with the flanged edged from the chip collector (MOD 07.52522). After accomplishment of the modification, this Amendment also specifies how to further monitor the MGB epicyclic reduction gear module magnetic plug. | |
| AD/EC 225/11 is now superseded and will be cancelled. | |
| The original issue of this Directive became effective on 20 April 2009. |
James Coyne
Delegate of the Civil Aviation Safety Authority
24 April 2009
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