AD/AT/22 Amdt 1 - Wing Centreline Splice Joint

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/AT/22. 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/22

Amdt 1

Wing Centreline Splice Joint 6/2003 DM

Applicability: Models AT-300, AT-301, AT-302, and AT-400A aircraft, all serial numbers, that have aluminium spar caps;

Models AT-400 aircraft, serial numbers 400-0244 through 400-0415, that have aluminium spar caps;

Models AT-300 and AT-301 aircraft, all serial numbers, that have aluminium spar caps and are, or have been converted to turbine power.

Requirement: Accomplish either the Requirement 1 spar lower cap replacement or the Requirement 2 spar lower cap repetitive inspections.

1. Replace each wing spar lower cap in accordance with the applicable maintenance manual, as follows:

1. All affected Models AT-300 and AT-301 aircraft that incorporate reciprocating engines and incorporate the wing spar centre splice joint modification in accordance with the following:

(i)       Snow Engineering Co. Service Letter No.55, Revised 23 October 2002; and,

(ii)    Snow Engineering Co. Service Letter No.70, Revised 23 October 2002.

b.         All affected Models AT-300 and AT-301 aircraft that incorporate reciprocating engines and do not incorporate the wing spar centre splice joint modification.

(i)       the wing spar centre splice joint modification may be incorporated on these aircraft to allow continued operation to 7,000 hours time in service as specified in Requirement 1.a. compliance of this Directive; and

(ii)    use the information specified in Requirements 1.a.(i) and 1.a.(ii) of this Directive to accomplish this modification.

c.         All affected AT-302, AT-400, and AT-400A aircraft with aluminium spar caps; and all affected Models AT-300 and AT-301 aircraft that incorporate aluminium spar caps and are, or have been converted to turbine power. Snow Engineering Co. Service Letter No.226 dated 17 December 2002, includes information on these aircraft.

2.        To repetitively inspect the wing lower spar caps instead of replacement; accomplish the procedures in Snow Engineering Process Specification No.197, Revised 4 June 2002, and Snow Engineering Co. Service Letter 220, dated 17 December 2002. To use this option, parts must be ordered and the spar lower cap replacement scheduled with an Airtractor authorised facility. Then inspect as follows:

1. For any affected reciprocating engine powered aircraft: initially inspect at the applicable compliance time in Requirement 1.a. or 1.b.of this Directive and repetitively inspect thereafter at intervals not to exceed 300 hours time in service. If the aircraft was previously inspected in accordance with Snow Engineering Co. Process Specification No.197, then credit can be taken for that inspection; inspect thereafter at intervals not to exceed 300 hours time in service. Apply previous inspections toward Requirement 2.a.(iii) (900 hours time in service requirement). Replace the wing spar lower caps before further flight after whichever of the following occurs first:

(i)       The date of the scheduled replacement;

(ii)    Cracks are found during any inspection allowed by Requirement 2 of this Directive; or,

(iii)  Upon accumulating 900 hours time in service after the initial inspection accomplished in accordance with Requirement 2.a. of this Directive.

b.         For any affected turbine engine powered aircraft: initially inspect at the compliance time in Requirement 1.c. of this Directive, and repetitively inspect thereafter at intervals not to exceed 300 hours time in service. If the aircraft was previously inspected in accordance with Snow Engineering Co. Process Specification No.197, then credit can be taken for that inspection; inspect thereafter at intervals not to exceed 300 hours time in service. Apply previous inspections toward Requirement 2.b.(iii) (600 hours time in service requirement). Replace the wing spar lower caps before further flight after whichever occurs first:

(i)       The date of the scheduled replacement;

(ii)    Cracks are found during any inspection allowed by Requirement 2 of this Directive; or,

(iii)  Upon accumulating 600 hours time in service after the initial inspection accomplished in accordance with Requirement 2.b. of this Directive.

Note: FAA AD 2003-06-01 Amdt 39-13088 refers.

2. Refer to Requirement 2.a. and 2.b. for compliance times/requirements. This Amendment becomes effective on 7 May 2003.

Background: The FAA received a report of an in- flight separation of a wing from a Model AT- 400A aircraft. Investigation revealed that fatigue caused the lower aluminium spar cap to fail across the 3/8- inch hole, 6.5 inches outboard of the fuselage centreline in the centre splice connection. The actions specified in this Directive are intended to detect and correct cracks in the centreline splice joint. Undetected cracks could eventually result in in- flight separation of the wing.

Amendment 1 is issued in response to a new FAA AD which further reduces the mandatory wing spar lower cap replacement times; in response to inspection results from FAA AD 2002-13-02.

The original issue of this Airworthiness Directive became effective on 24 July 2002.

David Villiers

Delegate of the Civil Aviation Safety Authority 2 May 2003

The above AD is notified in the Commonwealth of Australia Gazette on 7 May 2003.