AD/DHC-8/28 Amdt 1 - Underwing Fairing Angles (Cth)

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-8/28 Amdt 1

Underwing Fairing Angles 12/95

Applicability: DHC-8 aircraft, Models 311 and 315, serial numbers 240 through 279.

Requirement: Inspect the rear face of the left hand and right hand underwing fairing angles for cracks, in accordance with Part A of the Accomplishment Instructions in de Havilland Service Bulletin A8-53-46 Rev A.

Note: Transport Canada AD CF-93-10R1 refers.

Compliance: Inspect before 6930 flights or within 100 flights from 7 June 1993, which ever occurs later. Re-inspect at intervals not to exceed 6930 flights until replaced with new angles.

The Compliance of the initial issue of this Directive remains unchanged. This Amendment is effective from 9 November 1995.

Note: If an angle is replaced, the inspection requirement for the new angle reverts to that specified for the standard aircraft, which has a threshold of 40000 flights and a repeat interval of 8194 flights (Maintenance Task 5310/15K refers).

Background: A number of titanium fairing angles made for the model 301 were reworked to fit model 311 aircraft during manufacture. The rework entailed weld-filling three fastener holes and re-drilling the holes to suit the model 311 aircraft. The welds were made of commercially pure titanium, with a hardness of one third that of the angle parent material, and there is evidence that in some cases the holes may not have been fully plugged. As a result the fatigue durability of the reworked components P/N 85350927-107SP and -108SP, is unknown and more frequent inspections are required.