Applicability: All Jetstream Series 3100 and 3200 aircraft.

Requirement: Action in accordance with BAE Systems Service Bulletin 57-JA020740 Revision 2, or later EASA approved revision.

Note: UK CAA AD G-2006-0003 refers.

Compliance: Before 31 March 2006, unless already accomplished. Inspect thereafter as specified in the Requirement document.

This Amendment becomes effective on 6 March 2006.

Background: The manufacturer received reports of failed bolts fitted to frame 199 wing spigot post assembly on in-service aircraft. Investigation revealed fatigue failure, resulting from either incorrect bolts installed or bolt tightening torque being too low. Failure of these bolts severely compromises the structural integrity of the wing to fuselage attachment.

Amendment 1 added an alternative bolt part number and a compliance note, and excluded run-down torque in the torque figures.

Amendment 2 is issued in response to a new UK CAA AD, which relates to the need by Revision 2 of the Requirement document to check for correct washer installation.

Incorrect installation could lead to fretting and fatigue crack initiation in the fitting followed by failure or bending loads in the bolt leading to failure of the affected bolts. If left uncorrected, failure of these bolts or a wing fitting will severely compromise the structural integrity of the wing to fuselage attachment.

FMI: www.casa.gov.au