Commonwealth legislation

AD/DAUPHIN/49 - MRH Spherical Thrust Bearings/Attach Beams Attachment Bolts

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

This Airworthiness Directive requires operators of specified Eurocopter SA 365 and AS 365 Dauphin helicopters fitted with main-rotor spherical thrust bearing/attach beam attachment bolts to check the bolts' tightening torque and, if torque is under 12 m.daN, remove and inspect the spherical thrust bearing and replace it if cracked. The DGAC states the measure prevents cracking from bolt loosening. Operators pay for the torque checks, removals and any replacements; CASA fixes timing (initial when bolts are removed or by 550 flying hours after 31 Dec 1998, then every 550 hours).

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Current sections

Direct links to the current provisions in AD/DAUPHIN/49 - MRH Spherical Thrust Bearings/Attach Beams Attachment Bolts.

AD/DAUPHIN/49 - MRH Spherical Thrust Bearings/Attach Beams Attachment Bolts

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Eurocopter SA 360 and SA 365 (Dauphin) Series Helicopters

AD/DAUPHIN/49 MRH Spherical Thrust Bearings/Attach

Beams Attachment Bolts

14/98

Applicability: SA 365 helicopters, versions C, C1, C2, and C3, and AS 365 helicopters, versions N, N1, N2, and N3, fitted with main rotor head spherical thrust bearings/attach beam attachment bolts, all part numbers.

Requirement: Check the tightening torque load of both the spherical thrust bearing/attach beam attachment bolts in accordance with the instructions specified in paragraph 2B of Eurocopter SA 365C Service Bulletin (SB) No. 05.22, or AS 365N SB No. 05.00.39, as applicable.

If the tightening torque is less than 12 m. daN:

Remove the spherical thrust bearing and check for cracks. If a crack is found, replace the spherical thrust bearing.

Note: DGAC AD 98-383-044(A) and AD 98-384-047(A) refer.

Compliance: Initially, when the spherical thrust bearing attachment bolts are required to be removed, but at the latest before the accumulation of 550 flying hours after 31 December 1998; thereafter at intervals not to exceed 550 flying hours.

This Airworthiness Directive becomes effective on 31 December 1998.

Background: The DGAC requires the actions specified by this Directive in order to prevent the formation of cracks in the metal components of the spherical thrust bearings, due to increased stress resulting from possible loosening of the attachment bolts.

Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

1 AD/DAUPHIN/49 - MRH Spherical Thrust Bearings/Attach Beams Attachment Bolts