AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AT/23 and issues the following AD under subregulation 39.1 (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.
Airtractor AT-300, 400 and 500 Series Aeroplanes
AD/AT/23
Amdt 1
Aft Fuselage Structure Upper Longeron and Upper Diagonal Tube
10/2004
Applicability: Model AT-401, AT-401B, AT-402, AT-402A, and AT-402B aircraft, serial numbers 0716 through 1144.
Model AT-501, AT-502, AT-502A, AT-502B, and AT-503A aircraft, serial numbers 0037 through 0658.
Requirement: 1. For Models AT-401 and AT-401B aircraft, serial numbers 0716 through 1144:
Inspect the upper longeron and upper diagonal tube on the left hand side of the fuselage frame, just forward of the vertical fin front spar attachment, for cracks in accordance with Snow Engineering Co. Service Letter (SL) No. 218A, dated 10 November 2003, as specified in SL No. 195, re-issued 10 November 2003.
2. For Models AT-402, AT-402A, and AT-402B aircraft, serial numbers 0716 through 1144:
Inspect the upper longeron and upper diagonal tube on the left hand side of the fuselage frame, just forward of the vertical fin front spar attachment, for cracks in accordance with SL No. 218A, dated 10 November 2003, as specified in SL No. 195, re-issued 10 November 2003.
3. For Models AT-501, AT-502, AT-502B, and AT-503A aircraft, serial numbers 0037 through 0658:
Inspect the upper longeron on the left hand side of the fuselage frame, just forward of the vertical fin front spar attachment, for cracks in accordance with SL No. 195B, dated 10 November 2003, as specified in SL No. 195, re-issued 10 November 2003.
4. For Models AT-502A aircraft, serial numbers 0037 through 0658.
Inspect the upper longeron on the left hand side of the fuselage frame, just forward of the vertical fin front spar attachment, for cracks in accordance with SL No. 195B, dated 10 November 2003, as specified in SL No. 195, re-issued 10 November 2003.
Note: FAA AD 2004-15-15 Amdt 39-13749 refers.
Airtractor AT-300, 400 and 500 Series Aeroplanes
AD/AT/23 Amdt 1 (continued)
Compliance: 1. Initially inspect upon the accumulation of 1,250 total hours time in service or within the next 100 hours time in service after 30 September 2004, whichever occurs later. Inspect thereafter at intervals not to exceed 100 hours time in service, until the upper and diagonal longerons are replaced and modified in accordance with SL No. 218B, dated 10 November 2003.
2. Initially inspect upon the accumulation of 1,250 total hours time in service or within the next 100 hours time in service after the last inspection required by the original issue of this Directive, whichever occurs later. Inspect thereafter at intervals not to exceed 100 hours time in service, until the upper and diagonal longerons are replaced and modified in accordance with SL No. 218B, dated 10 November 2003.
3. Initially inspect upon the accumulation of 4,800 total hours time in service or within the next 100 hours time in service after 30 September 2004, whichever occurs later. Inspect thereafter at intervals not to exceed 100 hours time in service, until the upper longeron is replaced and modified in accordance with SL No. 195A, revised 10 November 2003.
4. Initially inspect upon the accumulation of 2,800 total hours time in service or within the next 100 hours time in service after 30 September 2004, whichever occurs later. Inspect thereafter at intervals not to exceed 100 hours time in service, until the upper longeron is replaced and modified in accordance with SL No. 195A, revised 10 November 2003.
This Amendment becomes effective on 30 September 2004.
Background: The FAA received reports of three occurrences of cracks found on the left hand upper longeron and upper diagonal support tubes where they intersect on the left side of the fuselage frame just forward of the vertical fin front spar attachment point, on Model AT-602 aircraft. The cracks were found by the pilot and/or ground crew when they noticed excessive movement of the empennage due to the loss of torsional rigidity.
Amendment 1 is issued in response to a new FAA AD, which adds certain AT-500 series aircraft to applicability, changes the compliance times, and incorporates new and revised manufacturer service information that contains a terminating action for the repetitive inspection requirement.
David Villiers
Delegate of the Civil Aviation Safety Authority 20 August 2004
The above AD is notified in the Commonwealth of Australia Gazette on 8 September 2004.