COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES SAAB SF340 Series Aeroplanes AD/SF340/48 Rudder Nose Rib 13/95 Applicability: Model SF 340A with serial numbers 004 through 159. Model 340B with serial numbers 160 through 369. Requirement: Action in accordance with SAAB Service Bulletin 340-55-032. Note: LFV AD 1-074 refers. Compliance: As specified in the Requirement Document with a revised effective date of 7 December 1995. Background: A report was received of a cracked nose rib on the front spar of the rudder. This condition could result in jamming between the fin and rudder due to deformation of the cracked nose rib web.