COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pitts S-1 and S-2 Series Aeroplanes AD/PITTS S-2/14 Fuselage Lower Longerons 11/86 DM Applicability: All models incorporating spring leg main landing gear and which have exceeded 200 hours time in service. Requirement: Inspect the fuselage lower longerons for cracks in the area of the MLG leg attachment, left and right sides. Pay particular attention to the weld clusters immediately forward and aft of the MLG leg. Compliance: Within 50 hours time in service after 6 October 1986 and thereafter at each issue of a new Maintenance Release. Background: One longeron has been found completely severed, and several have been found cracked, at the weld cluster aft of the MLG leg, at times in service ranging from 200 hours to 600 hours. One aircraft was also found to have cracks at the forward cluster.