AD/TB20/45 Wing Spar Lower Boom (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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.

Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes

AD/TB20/45 Wing Spar Lower Boom 10/2006

Applicability:

Model TB 20 and TB 21 aircraft, all serial numbers; without repair No. REP 20.031 implemented on both left hand and right hand sides.

Requirement:

Inspect the wing spar lower boom in accordance with the Accomplishment Instructions of SOCATA Service Bulletin No. 10-148 original issue, or later EASA approved revision.

When defect dimensions exceed the limits specified in the Requirement document, or if the defect is located out of the area depicted in Figure 2 of the Requirement document, then the Type 1 or Type 2 repairs are not valid.  A written report shall then be sent to the manufacturer as specified in paragraph A.5).  In this case, further flight is prohibited until SOCATA provides a repair solution or otherwise agrees to further flight.

Note:  EASA AD 2006-0123 refers.

Compliance:

Within 100 flight hours or one year after 28 September 2006, whichever occurs first.

This Airworthiness Directive becomes effective on 28 September 2006.

Background:

Reports were received of interference between the wing spar lower boom and wheel fairing attaching screw.  Such interference, unless corrected, could reduce the fatigue life of the wing spar.

David Villiers
Delegate of the Civil Aviation Safety Authority

28 July 2006