COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Piper PA-38 (Tomahawk) Series Aeroplanes AD/PA-38/19 Aileron Balance Weight Rib - Inspection 11/81 Applicability: All models PA-38-112 with S/Nos. 38-78A0001 to 38-81A0051 and 38-81A0105. Document: Piper SB No. 723. Compliance: Within 25 hours time in service after 22 September 1981, and thereafter at intervals not exceeding 100 hours time in until modified by incorporation of Piper Kit P/N 764 140. Background: The manufacturer has received reports of cracks developing in flange area of the aileron balance weight rib P/Nos. 77342-16 and -17.