COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Aerostar (Piper/Ted Smith) 600 and 700 Series Aeroplanes AD/TSA-600/23 Amdt 1 Three-Tank Fuel Quantity Indication - Installation 6/80 Applicability: All aerostar models 600, 601, 601P. Document: 1. Piper SB No. 600-81; or 2. FAA AD 79-01-05. Compliance: Within 100 hours time in service after 30 June 1980. Background: Installation of a three-tank fuel quantity indicator is part of a general improvement of fuel management for all models of Aerostar aeroplanes. The modification meets the requirements of FAA AD 79-01-05. A stay of compliance was effected while seeking technical justification for the modification from the FAA. The justification received from the FAA was such that no changes to the AD could be substantiated. However, the compliance date has been amended because of a time delay for the additional investigation.