COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 400 Series Aeroplanes AD/CESSNA 400/90 Amdt 2 Engine Mount Beams 2/89 Applicability: Model 404 with S/Nos 404-0001 to 404-0859. Requirement: Action in accordance with: 1. Cessna Service Bulletin MEB 86-7 and 2. Cessna Service Bulletin MEB 88-2; or an alternative scheme approved by the Authority. East-West Airlines Drawing C-71- 20-2137 is an approved alternative to SB MEB 88-2 for modification of the forward area of the engine mount beam. Note: Aircraft in compliance with the original issue of this Directive may require additional work in accordance with the Requirement Documents. Compliance: Inspections: In accordance with the Requirement Documents. Modifications: Unless already accomplished; before further flight if cracks are detected during inspections. Note: Embodiment of modifications, which constitute terminating action for this Directive, may be accomplished at any time prior to detection of cracks. Background: The manufacturer reports that cracking may occur in the region of the fwd and aft engine mount attachment holes on the engine mount beam. Amendment 1 to this Directive added the requirements of SB MEB 88-2, which details inspection and modification of the forward area of the engine mount beam. Amendment 1 also made it mandatory to modify the aft area in accordance with SB MEB 86-7. Amendment 2 recognises East-West Airlines Drawing C-71-20-2137 as an alternative scheme for modification of the forward area.