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. Cessna 207 Series Aeroplanes AD/CESSNA 207/39 Alternate Static Air Source Valve 7/2008 TX Applicability: Aeroplanes models listed in Table 1 that have an alternate static air source selector valve, part number (P/N) 2013142-18, installed after 19 November 2007. Table 1--Applicability for Aeroplanes that Could Have Had the Affected Part Installed as a Replacement Part or From Parts Held as Spares Model Serial Numbers (S/N) 207 All S/Ns Note 1: P/N 2013142-18 replaced P/Ns 2013142-9, -13 and -17. Requirement: 1. For aeroplanes listed in Table 1 - Either: a. Inspect the alternate static air source selector valve in accordance with Requirement 3, or b. Inspect the aeroplane's maintenance records to determine if the alternate static air source selector valve has been replaced since 19 November 2007 with P/N 2013142-18, if the valve has not been replaced no further action is necessary. Note 2: The Requirement 1.b. inspection and determination may be accomplished and certified for by the aeroplane operator, provided that they hold at least a private pilot's licence. 2. If the Requirement 1.b. determination indicates that a P/N 2013142-18 alternate static air source selector valve has been installed inspect the valve in accordance with Requirement 3. 3. Inspect the alternate static air source selector valve to assure that the part number identification placard is not obstructing the port as follows: a. Adjust the pilot and copilot seats as far aft as possible. b. Use a flashlight and mirror to inspect the alternate static air source selector valve to assure the port on the forward end of the valve is clearly visible and not covered by the part number identification placard. 4. If, during any Requirement 3 inspection, the alternate static air source selector valve port is found obstructed by the part number identification placard, remove the placard from the valve body, discard the placard and assure that the port is open and unobstructed. 5. Static air source selector valves P/N 2013142-18 installed as modification or replacement parts on or after the effective date of this Directive must be inspected in accordance with Requirement 3 prior to installation. Note 3: FAA AD 2008-10-02 Amdt 39-15508, which becomes effective on 12 May 2008, refers. Compliance: For Requirements 1, 2 and 3 - Before further flight after the effective date of this Directive. For Requirement 4 - Before further flight after the Requirement 1 inspection. For Requirement 5 - As of the effective date of this Directive. This Airworthiness Directive becomes effective on 13 May 2008. Background: The United States Federal Aviation Administration (FAA) has received reports of improper installation of the part number identification placard on alternate static air source selector valves of certain Cessna 172, 175, 180, 182, 185, 206, 207, 208, 210 and 303 series aeroplanes. The part number identification placard refers to alternative air source selector valves, part number 2013142-18, that were manufactured between 20 November 2007 and 18 February 2008. The part number identification placard was installed on the valve body in a location that covers the port, which is the inlet for static air reference into the valve. The problem was discovered during a quality control check. The FAA has advised that all parts held in stock at Cessna have been corrected and that Cessna has no way of verifying how many of these assemblies were manufactured and sent to the field with the part number identification placard installed over the alternate static air source selector valve port. The Civil Aviation Safety Authority (CASA) has no way of determining which aeroplanes have the remaining problem alternate static air source selector valve assemblies installed without having all of the affected aeroplanes and spares stock inspected. This condition, if not corrected, could result in the altimeter, airspeed and vertical speed indicators displaying erroneous indications. This could cause the pilot to react to incorrect flight information and possibly result in loss of control. CASA has varied the inspection requirements to allow the aeroplane operator to determine if a P/N 2013142-18 selector valve has been installed since 19 November 2007. James Coyne Delegate of the Civil Aviation Safety Authority 6 May 2008