COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna T303 Series Aeroplanes AD/CESSNA 303/9 Amdt 1 Slick Pressurized Magnetos - Flight Manual 2/90 Applicability: All Cessna T303 aircraft fitted with Slick Pressurized Magnetos model 6220 or 6224. Requirement: 1. Revise the AFM by adding the following: BEFORE TAKEOFF Perform a magneto check of each engine at 1,700 RPM as follows: Move ignition switch first to R position and note RPM. Next, move switch back to BOTH, to clear the other set of plugs. Then, move switch to the L position, note RPM and return the switch to the BOTH position. RPM drop should not exceed 150 RPM on either magneto or show greater than 50 RPM differential between magnetos. If there is doubt concerning operation of the ignition system, RPM checks at higher engine speed will usually confirm whether a deficiency exists. If the magneto check exceeds either of the above limits, both magnetos must be disassembled and inspected in accordance with Requirement 2 of AD/CESSNA 303/8; an entry to this affect is to be made in the Maintenance Release by the pilot. Note 1: The aforementioned amendment may be accomplished by inserting a copy of this AD into the relevant section of the AFM. Note 2: AD/CESSNA 303/8, FAA AD-25-04, and Teledyne Continental Service Bulletin M88-14 also refer. Compliance: Within 100 hours time in service after 20 April 1989 and concurrent with AD/CESSNA 303/8. Background: The Before Take Off check introduced by this AD requires that any magneto which exceeds the limits specified in the check must be placed unserviceable in the maintenance release by the pilot and subsequently disassembled and inspected in accordance with AD/CESSNA 303/8. Amendment 1 to this Directive is issued to correct certain documentation references only, and requires no additional work by operators.