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 39.1 (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 170, 172, F172, FR172 and 175 Series Aeroplanes AD/CESSNA 170/70 Fuel Mixture Setting 11/2001 Applicability: Cessna models 172R and 172S, all serial numbers. Requirement: 1. Carry out an engine idle speed and fuel mixture setting check by: 1. With engine oil temperature between 120 and 150 degrees Fahrenheit; and b. With the throttle hard at the ground idle stop; and c. Check the engine revolutions per minute (RPM) is between 575 and 625 RPM; and d. Check RPM rises between 10 and 50 RPM when the mixture control is rotated slowly counter clockwise to idle cut-off. The pilot in command, other than a student pilot, may carry out the engine idle speed and fuel mixture setting check. Compliance is recorded by entering in the Aircraft Log Book; "AD/CESSNA 170/70 carried out". Any discrepancy disclosed in carrying out the engine idle speed and fuel mixture setting check shall be recorded in the "Maintenance required" column of the aircraft maintenance release or equivalent document. 2. Amend the applicable Pilot's Operating Handbook (POH) and Pilot's Check List in accordance with the accomplishment instructions detailed in Cessna Service Bulletin SB01-11-02 The certificate of registration holder may carry out the amendment of the POH and Pilot's Check List; CAR (1988) 55 (4) refers. Note: FAA AD 2001-06-17 refers. Compliance: Unless previously accomplished, within 10 hours time in service from the effective date of this Directive. This Airworthiness Directive becomes effective on 1 November 2001. Cessna 170, 172, F172, FR172 and 175 Series Aeroplanes AD/CESSNA 170/70 (Continued) Background: This Directive has been issued to ensure the engine idle speed and fuel mixture setting is correct and that the Pilot's Operating Handbook (POH) provides the pilot with rich mixture engine restart procedures. The requirement addresses reports of rough engine operation resulting from improper engine servo fuel mixture settings. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 12 September 2001 The above AD is notified in the Commonwealth of Australia Gazette on 10 October 2001.