AD/DHC-8/26 Amdt 1 - Horizontal Stabiliser Attachment Bolts (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-8/26 Amdt 1

Horizontal Stabiliser Attachment Bolts 9/98

Applicability: DHC-8 Series 100 aircraft, models 102, 103, and 106, with serial numbers 003 through 349 excluding 316 and 345.

DHC-8 Series 300 aircraft, models 301, 311, and 314, with serial numbers 100 through 342 excluding 320, 338, and 340.

Requirement: Inspect the horizontal stabiliser attachment bolts at all six locations in accordance with the following instructions:

1. Carry out a detailed visual inspection of the bolts in the area of the head radius for indications of cracks or laps using a 10x magnifying glass.

2. Carry out a magnetic particle inspection of the bolts.

Note: Transport Canada AD CF-93-05R1 refers.

Compliance: For the mid spar attachment bolts: within 25 hours time in service after 22 January 1993.

For the front and rear spar attachment bolts: within 50 hours time in service after 22 January 1993.

The compliance of the original issue of this directive remains unchanged. This amendment becomes effective on 13 August 1998. Background: Several local reports were received of stabiliser mid spar attachment bolts with crack indications. Laboratory analysis revealed the cracks to be lap defects that were formed during manufacture. Small fatigue cracks from the laps were noted. The initial report findings were the result of compliance with SB 8-55-16, although the bolts did not have "PBF" marking on the head as specified in the service bulletin. As a precaution, the inspection was expanded to include the front and rear spar bolts.