Commonwealth legislation

AD/DHC-8/23 Amdt 3 - NLG Upper Drag Strut Trunnion Fittings

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legislative instrument

Plain English Summary

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This airworthiness directive requires operators of Bombardier DHC-8 Series 100 and 300 aeroplanes (specific serial numbers) with more than 500 flight cycles to inspect the nose-landing-gear upper drag strut trunnion fittings for cracks, torque-check fasteners, and replace fittings if cracks are found. It sets initial and recurring inspection intervals and allows terminating the inspections if a specified modification (8/2139) is installed. It matters to aircraft owners, maintenance organisations and pilots because cracking was found that could affect landing-gear support.

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Current sections

Direct links to the current provisions in AD/DHC-8/23 Amdt 3 - NLG Upper Drag Strut Trunnion Fittings.

AD/DHC-8/23 Amdt 3 - NLG Upper Drag Strut Trunnion Fittings

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

View image in the official source
Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/23

Amdt 3

NLG Upper Drag Strut Trunnion Fittings 11/95

Applicability: Model DHC-8, Series 100 and 300, serial numbers 003 through 395, except 011, 362, and 391, and which have accumulated more than 500 flight cycles.

Requirement: Action in accordance with the Accomplishment Instructions contained in de Havilland ASB A8-53-40 Revision A:

Visually inspect, in-situ, the drag strut trunnion fittings for cracks, and torque check all the fasteners securing the fittings.

If cracks are found on either fitting, replace both fittings with serviceable fittings prior to further flight.

2. (a) During the initial inspection, any fasteners found loose by the torque check must be replaced with new parts.

(b) During subsequent inspections, any fastener found loose by the torque check must be tightened properly.

3. For aircraft already fitted with de Havilland Modification 8/1880, re-instate (or commence) the repetitive inspection required by parts 1 and 2 above in accordance with the schedule below:

(a) If the aircraft has 900 or more flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed within the subsequent 100 flight cycles.

(b) If the aircraft has less than 900 flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed at or before the due date of the actual 1000 flight cycle interval, determined from the last inspection (or incorporation of Modification 8/1880).

Incorporation of de Havilland Modification 8/2139 (Introduction of New Trunnion Fittings and Fasteners for Drag Link of Nose Landing Gear) provides terminating action to the inspection requirements of this Directive. De Havilland Service Bulletin 8-53-49, dated 30 June 1995, provides approved instructions to incorporate Modification 8/2139 for aircraft not incorporating this modification during production.

Note: Transport Canada AD CF-92-18R3 refers.

Compliance: Initially, within 500 flight cycles after 12 November 1992, unless already accomplished during the last 500 flight cycles; and thereafter at intervals not to exceed 1000 flight cycles.

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

The compliance of the initial issue of this Directive remains unchanged. This Amendment is effective from 12 October 1995.

Background: Cracks have been found in the two trunnion fittings that retain and support the nose landing gear upper drag strut. Investigations have indicated that this cracking problem is caused by ground handling loads that appear to be higher than originally predicted. This condition may be further aggravated by loose fasteners.

Amendment 1 introduced optional terminating action. Amendment 2 rescinded the terminating action provided by an earlier issue of the AD. This action was prompted by reports that, due to bolt head gapping, installation difficulties have been encountered during incorporation of Modification 8/1880 on the aircraft, resulting in improper attachment of the fitting which, in turn, may cause the bolts to lose pre- tension.

Amendment 3 is issued to introduce optional terminating action to the inspection requirements of this Directive.

Source text

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

1 AD/DHC-8/23 Amdt 3 - NLG Upper Drag Strut Trunnion Fittings

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/23

Amdt 3

NLG Upper Drag Strut Trunnion Fittings 11/95

Applicability: Model DHC-8, Series 100 and 300, serial numbers 003 through 395, except 011, 362, and 391, and which have accumulated more than 500 flight cycles.

Requirement: Action in accordance with the Accomplishment Instructions contained in de Havilland ASB A8-53-40 Revision A:

Visually inspect, in-situ, the drag strut trunnion fittings for cracks, and torque check all the fasteners securing the fittings.

If cracks are found on either fitting, replace both fittings with serviceable fittings prior to further flight.

2. (a) During the initial inspection, any fasteners found loose by the torque check must be replaced with new parts.

(b) During subsequent inspections, any fastener found loose by the torque check must be tightened properly.

3. For aircraft already fitted with de Havilland Modification 8/1880, re-instate (or commence) the repetitive inspection required by parts 1 and 2 above in accordance with the schedule below:

(a) If the aircraft has 900 or more flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed within the subsequent 100 flight cycles.

(b) If the aircraft has less than 900 flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed at or before the due date of the actual 1000 flight cycle interval, determined from the last inspection (or incorporation of Modification 8/1880).

Note: Transport Canada AD CF-92-18R3 refers.

Compliance: Initially, within 500 flight cycles after 12 November 1992, unless already accomplished during the last 500 flight cycles; and thereafter at intervals not to exceed 1000 flight cycles.