COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
De Havilland DHC-1 (Chipmunk) Series Aeroplanes
AD/DHC-1/31
Amdt 1
Fin Rear Spar 1/96
Applicability: All English production aircraft.
Requirement: Inspect the fin structure for cracks and corrosion in accordance with paragraphs 2, 3 and 5 of British Aerospace Technical News Sheet (TNS) CT (C1) No. 156 Issue 4. Conduct the dye penetrant inspections in accordance with CAO 108.10.
Modifications H283 and H360 performed in accordance with paragraphs 3 and 5 respectively of TNS No. 156 Issue 4, cancel the re-inspection requirements of paragraphs 3 and 5 respectively.
Compliance: Inspect in accordance with paragraphs 2, 3, and 5 within 3 years or 600 hours, whichever occurs first, since the last inspection.
Thereafter perform all the Requirement inspections at intervals not to exceed 3 years or 600 hours, whichever occurs first.
This Amendment is effective from 4 May 1996.
Background: British Aerospace has reported that cracks have been found in the fin rear spar at three critical locations, and that corrosion has been found in the internal fin structure. Amendment 1 incorporates Issue 4 of TNS No. 156, which revises paragraph 5 inspection interval from 6 years or 600 hours, to 3 years or 600 hours.