14 January 2000
This revision to AV-99-03, dated 15 July 1999, has been published to clarify the description of the affected hardware and to correct the references to the Illustrated Parts Breakdowns.
An SDR reported cracks under the nutplates on the passenger seat bulkhead frame P/N 206-033-107-049 on a Model 206L helicopter. The correct attach screws P/N 120-079-10-12 and washers P/N 140-017-10SC had been replaced with unauthorized AN970 washers and AN3 bolts, which are longer than the original screws. The installation of the AN3 bolts indented the frame, initiating the fatigue cracking.
If left uncorrected, the integrity of the frame is compromised and the damage may spread to surrounding structures. Cracks were also reported on the inner skin and these could migrate up to the frame.
This cracking can only be found after removal of the interior. Therefore, Transport Canada strongly recommends an immediate inspection to confirm the use of the proper screws and washers at this location as per the applicable Illustrated Parts Breakdowns (IPB). If a substitute bolt is found, the removal of the interior and close inspection of the frame for cracking is required.
The following Bell Illustrated Parts Breakdowns refer:
For further information contact a Transport Canada Centre, or call Mr. Bogdan Gajewski, Continuing Airworthiness, Ottawa, telephone (613) 952--4450, facsimile (613) 996-9178 or e-mail firstname.lastname@example.org.
For Director, National Aircraft Certification
Chief, Continuing Airworthiness