Document ID: chunk:federal_register_of_legislation:F2008L01342:body:0:p3
Version: federal_register_of_legislation:F2008L01342
Segment Type: other
Provision Reference: 
Character Range: 5497–8367

the wing spar centre splice joint modification or the required wing spar lower cap replacement is done.

                  c. For all affected Models AT-300 and AT-301 aircraft with reciprocating engines that do incorporate the wing spar centre splice joint modification accomplished in accordance with Requirement 2.b:

                  Upon reaching the safe life limit of 7,000 total hours time in service on either wing spar lower cap or within 25 hours time in service after 7 May 2003 (the compliance time of the previous issue of this Directive), whichever occurs later; then replace each time the safe life limit of 7,000 total hours time in service on either wing spar lower cap is reached.  After each replacement, inspect as specified in Requirement 1 until the wing spar centre splice joint modification or the required wing spar lower cap replacement is done.

                  d. For all affected AT-302, AT-400, and AT-400A aircraft with aluminium spar caps; and all affected Models AT-300 and AT-301 aircraft with aluminium spar caps that are, or have ever been converted to turbine power:

                  Upon reaching 4,450 total hours time in service on either wing spar lower cap or within 25 hours time in service after 7 May 2003 (the compliance time of the previous issue of this Directive), whichever occurs later; then replace each time the safe life limit of 7,000 total hours time in service on the wing spar lower cap is reached.  After each replacement inspect as specified in accordance with Requirement 1, until the required wing spar lower cap replacement is done.

             Note:  FAA AD 2008-09-10 Amdt 39-15491 refers.
Compliance:  As specified in the Requirement section of this Directive.
             This Amendment becomes effective on 8 May 2008.
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 further reduced the mandatory wing spar lower cap replacement times; in response to inspection results from FAA AD 2002-13-02.

   Amendment 2 is issued in response to a new FAA AD, which was prompted by a recent report of cracks found on a Model AT-301 aircraft at hours below the specified modification time.  A repetitive eddy-current inspection is added to the AD requirements.

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

David Villiers
Delegate of the Civil Aviation Safety Authority

6 May 2008