COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Hot Air Balloons AD/BAL/18 Trivents 5/97 Applicability: Thunder and Colt balloon envelopes SN 3528, CN 3553, CN 3688, CN 3719, CN 3746, CN 3825, CN 3833, CN 3835, CN 3845, CN 3886, CN 3891, CN 3922, CN 3949, CN 3956, and CN 4026. Requirement: 1. Inspect the red line attachment on the trivent flap for damage to the stitching at the ends of the attachment loop in accordance with Cameron Balloons Ltd (Thunder & Colt) Service Bulletin SB3 Issue 1 revision C. 2. Reinforce the attachments on the Trivent flap in accordance with Cameron Balloons Ltd Service Bulletin SB3 Issue 1 revision C. Note: UK CAA AD 003-01-97 refers. Compliance: Unless already accomplished: 1. Before every flight after 24 April 1997; until Requirement 2 is accomplished. 2. Within 20 hours time in service after 24 April 1997. This Airworthiness Directive becomes effective on 24 April 1997. Background: This Directive action is required to ensure that all the attachments on the centreline of the flap are adequately reinforced.