Applicability: Model SA 365 N, and N1 helicopters, Model AS 365 N2 and N3 helicopters, and Model SA 365 C, C1, C2, and C3 helicopters; delivered before 27 March 2006, and equipped with a main rotor hub-to-main rotor mast (MRH/mast) bolted attachment assembled by Eurocopter.

Requirement: 1. On MRH/mast assemblies affected by Applicability section of this Directive, and having logged less than 280 flight hours: Check the tightening torque of the MRH/mast assembly attachment bolts, in accordance with paragraph 2.B. of Eurocopter AS 365N Alert Service Bulletin (ASB) No. 62.00.22, or SA 365 C ASB No. 65.44, as applicable.

2. On MRH/mast assemblies affected by Applicability section of this Directive, and having logged more than 280 flight hours:

Check the tightening torque of the MRH/mast assembly attachment bolts, in accordance with paragraph 2.B. of Eurocopter AS 365N ASB No. 62.00.22, or SA 365 C ASB No. 65.44, as applicable.

Note: EASA Emergency AD 2006-0084-E refers.

Compliance:

1. Within 300 flight hours after 13 April 2006.
2. Within 20 flight hours after 13 April 2006.

This Airworthiness Directive becomes effective on 13 April 2006.

Background: Several reports were received of tightening torque loss detected on the main rotor hub-to-main rotor mast bolted attachment on Eurocopter assembled attachments with less than 300 operating hours. A loss of tightening torque can lead to deterioration of the MRH/mast attachment and possible loss of the main rotor.

FMI: www.casa.gov.au