AD/CESSNA 336/11 Amdt 3 - Wing Front and Rear Spars - Inspection (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/CESSNA 336/11 Amdt 2 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.

Cessna 336 Series Aeroplanes AD/CESSNA 336/11 Amdt 3 Wing Front and Rear 10/2005 Spars - Inspection

Applicability: Models 336 with the following serial numbers 336-0001 through 336-0195. Requirement: Inspect the front and rear spars for cracking in accordance with Cessna SL ME78-2 Supplement No. 1 except that in connection with the front spar inspection the eddy current test sensitivity shall be established so that a 10% full scale meter deflection is obtained from a slot .030" + .003" deep, .060" + .003" long and .010" maximum width, machined in the wall of a 3/16" diameter hole in an aluminium alloy test block.

Note 1: FAA AD 78-09-05 also refers.

Note 2: A suitable test block is Nortec Part No. TB-12.

Note 3: Scoring of bolt holes can cause spurious eddy current indications of cracking and may be the cause of future fatigue crack initiations. Great care must therefore be taken when removing the subject bolts. Compliance: Inspect both the front and rear spars in accordance with the times specified for the rear spar in "Action Required" Section of Cessna SL ME78-2 Supplement No. 1 except that for aircraft incorporating Robertson Aircraft Corporation Modification to United States STC 1627 WE a reduction of 1000 hours in the inspection threshold and 100 hours in inspection intervals shall apply. This exception is subject to change should fatigue substantiating data on the Robertson conversion be supplied to the Authority. This Amendment becomes effective on 29 September 2005. Background: Amendment 2 was issued to clarify the eddy current test block specifications.