1AD/R22/27 - Vertical Fin Attachments

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Robinson R22 Series Helicopters

AD/R22/27 Vertical Fin Attachments 11/86 DM

Applicability: All models fitted with vertical fin to horizontal stabilizer attachment brackets which have exceeded 500 hours time in service.

Requirement: 1. Check the lower vertical fin for looseness of attachment which could indicate possible incipient failure of the attachment brackets.

2. Remove the lower vertical fin and

(a) visually inspect for fretting on the faying surfaces in the vicinity of the attachment bolts;

(b) inspect the fin attachment brackets in the horizontal stabilizer for cracking in the vicinity of the fin attachment bolts using a dye penetrant technique in accordance with ANO 108.10.

Compliance: For para 1: At each daily inspection, until inspected in accordance with para 2.

Note: This inspection may be accomplished by the pilot-in-command, in which case the precise A.D. reference shall be entered in a certification made on the Maintenance Release coincident with that for the daily inspection.

For para 2: Prior to exceeding 25 hours time in service after 22 September 1986, and thereafter at each issue of a new Maintenance Release.

Background: There have been two reported instances of cracking in the vertical fin attachment brackets, one of which caused an accident when the fin separated in flight.