AD/At/27 Amdt 2 Wing Lower Spar Cap (Cth)

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/27 Amdt 1 and issues the following 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.

Airtractor AT-300, 400 and 500 Series Aeroplanes

AD/AT/27 Amdt 2 Wing Lower Spar Cap 6/2009

Applicability:

Model AT-400, AT-401, AT-401B, AT-402, AT-402A, and AT-402B aircraft, with serial numbers specified in FAA AD 2006-08-08 R1.

Requirement:

Action in accordance with the technical requirements of FAA AD 2006-08-08 R1 Amdt 39-15849.

Report any cracks to CASA within 10 days of the crack finding via the SDR system, providing all details requested by FAA AD 2006-08-08 R1 inspection report form.

Note:  The Requirement document can be obtained through the FAA web site:

or by contacting

[email protected]

Compliance:

As specified in the Requirement document, with a revised effective date of
4 June 2009.

This Amendment becomes effective on 4 June 2009.

Background:

The FAA received in-service reports of fatigue cracking of the wing main spar lower cap 3/8-inch bolt hole at a time below the safe life limit established for applicable aircraft in FAA AD 2002-11-05 (AD/AT/20 Amdt 3 and AD/AT 800/3 Amdt 2).  Undetected fatigue cracking in the wing main spar lower cap could result in failure of the spar cap, and lead to wing separation and loss of control of the aircraft.

Amendment 1 was issued in response to a corrected issue of the FAA AD Requirement document, which introduced numerous changes to the FAA AD text.

Amendment 2 is issued in response to a revision of the related FAA AD, which was prompted by information received to update inspection intervals for the Models
AT-401B, AT-402A and AT-402B aircraft based on a revised damage tolerance analysis.  The revised FAA AD retains the currently required actions, but reduces the number of repetitive inspections for all affected Model AT-401B aircraft and certain Models AT-402A and AT-402B aircraft.

David Villiers
Delegate of the Civil Aviation Safety Authority

17 April 2009