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/P68/23 Amdt 3 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.
Partenavia P68 Series Aeroplanes
AD/P68/28 Amdt 4
Engine Mount Fittings
6/2013
 
Applicability:
All Models.

Requirement:
Action in accordance with Partenavia SB No 70 Rev 2.
Note: Para 1-13B of the Requirement document specifies 75/1000 of local thickness, e.g. if local thickness is 3 mm (0.125") then max allowable corrosion depth is 0.24 mm (0.009").

Compliance:
Section 1: Unless already accomplished in accordance with previous revisions of the Requirement document, prior to the issue of the next Maintenance Release after 25 October 1989, or prior to 5 calendar years since the date of manufacture. Thereafter in accordance with Section 3.
Section 3: Every 500 hours time in service or 2 years, whichever happens first, after compliance with Section 1.

 
This Amendment becomes effective on 29 March 2013.

Background:
Reports of corrosion and extensive cracking of the engine mount attachment fittings have been received.
Amendment 3 clarified the 75/1000 allowable corrosion depth and called for a re‑inspection where 1.9 mm (0.075") may have been used as the acceptance/rejection criterion.
Amendment 4 makes reference to Partenavia Service Bulletin No 70 rev 2.

 
Peter Nikolic
Delegate of the Civil Aviation Safety Authority
12 March 2013