COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Pilatus Porter PC-6 Series Aeroplanes
AD/PC-6/38 Horizontal Stabiliser Inspection 7/93
All Pilatus Porter PC-6 series aircraft.
Retire the horizontal stabiliser; or
Modify the horizontal stabiliser and inspect for cracks in accordance with a scheme approved by the Authority.
Aeronautical Designs Australia Pty Ltd EO-934 is an approved scheme for the purpose of this Directive.
Retire before 10000 hours component time in service; or
Modify and inspect before 10000 hours component time in service. Re-inspect at intervals not exceeding 100 hours.
The Pilatus Porter horizontal stabiliser has a history of fatigue cracking in service.
Inspection access to some cracking sites is very restricted.
This AD gives two options: retire before cracks are likely to start; or improve access and inspect.