AD/Convair/16 Wing Front Spar Lower Rail (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes

AD/CONVAIR/16 Wing Front Spar Lower Rail 5/2006

Applicability:

Model 340 and 440 aircraft, and all such model aircraft converted to turbopropeller power.

Requirement:

1.    For aircraft with 23,500 or more hours time in service:

Remove the wing leading edge and perform a visual inspection of the left and right wing front spar lower rail between wing stations 240 and 490 for cracks.  If cracking is detected, repair in accordance with Requirement 3 before further flight.

2.    For aircraft with less than 23,500 hours time in service:

Remove the wing leading edge and perform a visual inspection of the left and right wing front spar lower rail between wing stations 240 and 490 for cracks.  If cracking is detected, repair in accordance with Requirement 3 before further flight.

During the inspections pay particular attention to the areas immediately adjacent to the leading edge joints at wing stations 248, 264, 363, and 484.  All reported cracks have originated in the rail forward flange at or near the leading edge attach screw holes.

3.    If a crack is confined to the wing front spar lower rail, repair in accordance with General Dynamics/Convair Service Engineering Report No.057-0/67-340-64/440-64/640-35, Revision 1 or later FAA Approved revision.  If a crack extends beyond the spar rail into adjacent components, contact the Type Certificate Holder for technical advice.

The repetitive inspections required in Requirements 1 and 2 may be discontinued when all cracks, if any, have been repaired in accordance with Requirement 3, and unless already accomplished in accordance with Requirement 3, a reinforcing strap has been installed in accordance with details (a) and (b), Figure 1, of General Dynamics/Convair Service Engineering Report No.057-0/67-340-64/440-64/640-35, Revision 1.

Note:  FAA AD 68-10-04 Amdt 39-2247 refers.

Compliance:

1.    Unless the initial inspection is already accomplished, within 300 hours time in service after 11 May 2006 unless accomplished within the last 700 hours time in service.  Thereafter at intervals not to exceed 1,000 hours time in service.

2.    Before the accumulation of 23,800 hours time in service.  Thereafter at intervals not to exceed 1,000 hours time in service.

3.    Before further flight.

This Airworthiness Directive becomes effective on 11 May 2006.

Background:

The FAA received several reports of cracks in the wing front spar lower rail.  Undetected cracking could result in failure of the outboard wing.

David Villiers
Delegate of the Civil Aviation Safety Authority

31 March 2006