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. PZL 104 (Wilga) Series Aeroplanes AD/WILGA/5 Fuselage Front Posts 9/2009 Applicability: Model PZL-104 Wilga 35, 35A and 80 aircraft, all serial numbers. Requirement: 1. For aircraft which have accumulated 12 years or more from the last overhaul at the effective date of this Directive: a. Inspect the fuselage front posts for corrosion in accordance with paragraph 6.A. of EADS PZL "Warszawa-Okecie" S.A. Mandatory Bulletin (MB) No. 1109185 initial issue, or later EASA approved revision, for PZL-104 Wilga 35 and 35A aircraft; and MB No. 10409036 initial issue, or later EASA approved revision, for PZL-104 Wilga 80 aircraft. If serious corrosion damage is detected that meets the criteria defined in paragraph 6.A.c of the applicable Requirement document, before further flight, repair in accordance with an approved repair scheme or replace with a serviceable part, as necessary. b. Replace the padding of the rear glass in accordance with paragraph 6.C. of MB No. 1109185 initial issue, or later EASA approved revision, for PZL-104 Wilga 35 and 35A aircraft; and MB No. 10409036 initial issue, or later EASA approved revision, for PZL-104 Wilga 80 aircraft. 2. For all aircraft: Amend the approved operator's aircraft maintenance programme to incorporate the applicable tasks as described in the relevant PZL-104 Wilga 35 or PZL-104 Wilga 80 Maintenance Manuals titled "Maintenance Instructions and Scheduled Inspections". Note: EASA AD 2009-0072R1 refers. Compliance: For Requirement 1 and 2: Within 6 months after 27 August 2009. This Airworthiness Directive becomes effective on 27 August 2009. Background: An inspection of a PZL-104 Wilga aircraft with a long operational background revealed severe corrosion of the steel front fuselage structural elements. Such corrosion, if left uncorrected, could lead to loss of strength of the structural front posts and consequent reduction of the structural integrity of the aircraft. David Villiers Delegate of the Civil Aviation Safety Authority 15 July 2009