COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 400 Series Aeroplanes AD/CESSNA 400/101 Amdt 1 Seat Back Reinforcing Strap 7/94 Applicability: Aeroplanes in the Serial Number ranges: 401B0101 to 401B0221 402B0354 to 402C1020 414-0151 to 414A1212 421B0101 to 421C1807 425-0002 to 425-0236 Requirement: Action in accordance with Cessna MEB 89-3 Rev 1 and CQB 90-7 as applicable. Compliance: Within 100 hours time in service after 1 April 1993 for all applicable models, except the model 425 which is, within 100 hours time in service after 23 June 1994. Background: In Australia there is a history of seat back failure in the aircraft referred to in the MEB. The most recent being a total failure in IMC conditions, which in normal single pilot operation would have resulted in total loss of control near the ground. Amendment 1 changes the Applicability to include the model 425 which has similar seats. It also includes Revision 1 to the MEB which requires no further work.