AD/AC/93 Amdt 2 Wing to Fuselage Attachment (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/AC/93 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.

Twin Commander (Gulfstream/Rockwell/Aerocommander 500, 600 and 700) Series Aeroplanes

AD/AC/93 Amdt 2 Wing to Fuselage Attachment 5/2008

Applicability:

All models, all serial numbers.

Requirement:

1.    For all aircraft except models 520 and 560, gain access to, and inspect, the wing forward attachment brackets and straps (left and right wing) in accordance with PART 1 of Twin Commander Service Bulletin (SB) 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997.  Replace any cracked part or repair the aircraft using an approved scheme.

Note 1:  The access holes specified in SB 223 are not mandatory.  Alternative access provisions installed in the aircraft in accordance with a CAR 35 approved scheme are acceptable, provided that sufficient access to carry out the required inspections is available.  For aircraft modified with a titanium leading edge, by way of an STC, installation of access holes in the leading edge is not possible.  It will be necessary to remove the wing root fairing to accomplish the inspection on these aircraft.

2.    Inspect for cracks in accordance with PART II of Twin Commander Service Bulletin (SB) 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice No. 2, dated August 18, 1997.  Replace any cracked part or repair the aircraft using an approved scheme.

3.    For all aircraft except models 690C and 695, inspect in accordance with PART III of Twin Commander Service Bulletin (SB) 223, dated October 24, 1996 as amended by Revision Notice No. 1, dated May 8, 1997 and Revision Notice
No. 2, dated August 18, 1997.  Repair any cracks found during this inspection using an approved scheme.

Note 2:  Twin Commander SB 213, mandated by a separate FAA AD, specifies inspections equivalent to Requirement 3 for models 690C and 695.

Note 3:  FAA AD 98-08-19 refers.

Compliance:

1.    For requirement 1, unless already accomplished, inspect before 6000 hours total time in service (TIS) or before 100 hours TIS after 16 July 1998, whichever occurs later.  Thereafter, re-inspect at intervals not to exceed 1000 hours time in service.  Replace or repair any cracked part before further flight.  Compliance with the initial issue of this directive is considered to be prior accomplishment of Requirement 1.

2.    For requirement 2, inspect in accordance with the table below.

Model	Initial Inspection	Repeat Inspection for Requirement 2
All models except 520 and 560.	Before further flight, if cracks are found after 15 July, 1998 when complying with Requirement 1.  Aircraft that have been inspected in accordance with the initial issue of this directive (or per Requirement 1) before 16 July, 1998, and were found to have  cracks, are to be inspected before 100 hours TIS after 16 July, 1998 unless PART II has already been accomplished.	If no cracks are found, repeat inspections at intervals not to exceed 1000 hours TIS. If cracks are found, replace or repair the cracked item and continue to inspect at intervals not to exceed 6000 hours TIS.
Model 520 and 560.	Before 6000 hours total TIS or before 100 hours TIS after 16 July 1998, whichever occurs later.	If no cracks are found, repeat inspections at intervals not to exceed 1000 hours TIS. If cracks are found, replace or repair the cracked item before further flight and continue to inspect at intervals not to exceed 6000 hours TIS.

3.    For requirement 3, inspect as per the following table.

Model	Initial Inspection	Repeat Inspection for Requirement 3
All affected non-pressurised models	Before 12000 hours total TIS, or before 100 hours TIS after 16 July 1998, whichever occurs later.	If no cracks are found, repeat inspections at intervals not to exceed 1000 hours TIS. If cracks are found, replace or repair the cracked item before further flight and continue to inspect at intervals not to exceed 1000 hours TIS.
All affected pressurised models.	Before 6000 hours total TIS, or before 100 hours TIS after 16 July 1998, whichever occurs later.	If no cracks are found repeat inspections at intervals not to exceed 1000 hours TIS. If cracks are found, replace or repair the cracked item before further flight and continue to inspect at intervals not to exceed 1000 hours TIS.

This Amendment becomes effective on 8 May 2008.

Background:

Cracks have been found on several affected aircraft in the fuselage frame and surrounding structure at the wing leading edge attachment.  Left undetected and uncorrected the structural integrity of the wing to fuselage attachment may be affected and cause catastrophic structural failure.

This amendment is issued to correct a typographical error to the FAA AD reference in Note 3.  There is no change to the requirement or compliance section of this AD.

Amendment 1 of this airworthiness directive became effective on 9 November 2005.

The original issue of this airworthiness directive became effective on 9 November 1995.

James Coyne
Delegate of the Civil Aviation Safety Authority

27 March 2008