AD/EC 225/3 Main Rotor Blade De-Icing System Harness Connectors (Cth)
AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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 225/3 | Main Rotor Blade De-Icing System Harness Connectors | 11/2008 DM |
Applicability: | EC 225 LP helicopters, all serial numbers, equipped with main rotor blade de-icing harnesses part number 42994. |
Requirement: | 1. Check for correct tightness the five main rotor blade de-icing harness connectors on the slip-ring assembly side, in accordance with the accomplishment instructions of the Eurocopter EC 225 LP Alert Service Bulletin (ASB) 05A006 dated 21 December 2006. |
| 2. If not previously accomplished in accordance with European Aviation Safety Agency (EASA) Emergency Airworthiness Directive (EAD) 2007-0012-E for each of the five main rotor blade de-icing harness connectors on the slip-ring assembly side, check that the locking system operates correctly and fit the harness connectors with heat-shrinkable sleeves, as instructed in the accomplishment instructions of the ASB 05A006. | |
| 3. Check for correct tightness the five main rotor blade de-icing harness connectors on the slip-ring assembly side, in accordance with the accomplishment instructions of ASB 05A006. | |
| 4. Install a heat-shrinkable sleeve on the harness connector, in accordance with the accomplishment instructions of ASB 05A006. | |
| Later revisions of ASB 05A006, approved by the EASA, are acceptable for compliance with the relevant parts of this Directive. | |
| Note: EASA EAD 2007-0012-E refers. | |
Compliance: | For Requirement 1 - Before each flight from 29 August 2008 (the effective date of this Directive) until compliance with Requirement 2 is achieved. |
| For Requirement 2 - Within the next 50 hours time in service (TIS) or 3 months, whichever occurs first, after 29 August 2008. | |
| For Requirement 3 - Within the next 85 hours TIS after initial compliance with Requirement 2 of this Directive or paragraph 2 of EASA EAD 2007-0012-E or the last compliance with paragraph 3 of EASA EAD 2007-0012-E and thereafter at intervals not to exceed 85 hours TIS. |
| For Requirement 4 - Each time a main rotor blade de-icing harness connector is disconnected and reconnected. | |
| This Airworthiness Directive becomes effective on 29 August 2008. | |
Background: | An occurrence involving the disconnection of a main rotor blade de-icing harness was covered by Direction Générale de l’Aviation Civile of France (DGAC) AD Since then, during a flight-related check, another connector of the main rotor blade de-icing harness was found not fully tightened on the slip-ring assembly side. No case of failure of the connector of the same harness on the blade side has been reported so far to EASA. Regarding the latest case of connector disconnection, investigations revealed that the loss of the locking function is due to the failure of a self-locking spring ring inside the connector. In the event of such a situation, the de-icing function on all main rotor blades is lost, which can be detrimental for the safety of the helicopter flying in icing conditions. Therefore, this Directive is issued in order to prevent untimely disconnection of the incriminated de-icing harness connector. |
James Coyne
Delegate of the Civil Aviation Safety Authority
25 August 2008
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