COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bell Helicopter Textron 212 Series Helicopters
AD/BELL 212/28
Amdt 2
Vertical Fin Forward Spar 2/88
Applicability: All Bell 212 helicopters which have P/N 212-030-447-001, or -101 spar caps in the vertical fin forward spar.
Requirement: Inspect all -001 spar caps, and those -101 caps which are less than 0.190 inches thick when measured as shown in Bell ASB 212-86-38 using the inspection method described in Bell Technical Bulletin 212-81-50 Part 1.
Compliance: At intervals not exceeding 120 hours component time in service. Inspection is not necessary once either of the following modifications has been accomplished:
- Installation of a doubler in accordance with Part III of Bell Technical Bulletin 212-81-50;
b. Installation, in accordance with Bell ASB 212-86-38, of a new spar cap P/N 212- 030-447-101, providing it has a cap thickness of not less than 0.190 inches when measured as shown in Part I of Bell ASB 212-86-38, or has been reinforced in accordance with Part II of this same ASB.
Background: There have been numerous cracked -001 spar caps. A batch of the replacement -101 spar caps was made undersize. The static strength of the undersize caps is satisfactory if they are thicker than 0.155 inches, however, the fatigue strength of the caps less than 0.190 inches thick has not been demonstrated.
The content of AD/BELL 212/34 is now incorporated into this Directive because the two Directives were closely inter-related. AD/BELL 212/34 is now cancelled.