COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 400 Series Aeroplanes AD/CESSNA 400/46 Amdt 1 Wing Tip Strobe Light - Inspection 7/79 Applicability: All models S/Nos. 401B0001 thru 401B0300, 402B0001 thru 402B0912, 414-0001 thru 414-0649, 421B0001 thru 421B0922 and 421B0924 thru 421B0927 equipped with strobe lights installed in wing tip fuel tank nose cap except those aeroplanes having Symbolic displays P/N 30-0005, 30-0199-3 and 701133-1; Whelen Engineering Co. Inc. P/N A430; and Grimes Manufacturing Co. P/N 30-0515-5, 30- 1172-1, 30-0531-1 and 30-0467-5, strobe lights. Requirement: 1. Deactivate the strobe light system by installing a guard over the switch and/or by pulling and locking the circuit breaker so that it cannot be inadvertently reset, or by any other suitable means. 2. Systems having Grimes P/N 30-0515-1 strobe lights may be reactivated upon the installation of Grimes P/N 31-1723-5 or 30-1171-1 cover plates in accordance with Cessna SL ME75-16. These cover plates may be identified by the presence of two quench tubes protruding into the light assembly from the end plate. 3. Do not reactivate other non excepted strobe light assemblies until data, showing that the strobe lights are explosion proof, has been submitted to and approved by the Secretary. Compliance: Within 100 hours time in service after 30 July 1976.