COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Schweizer (Hughes) 269 Series Helicopters AD/HU 269/65 Amdt 1 Tail Rotor Blade Corrosion 7/86 Applicability: All models, fitted with tail rotor blades P/No. 269A6035-21 with S/Nos. prior to 0877 and tail rotor blades P/No. 269A6035-23 with S/Nos. prior to 2710. Requirement: Action in accordance with Hughes SIN No. N-162. Note: FAA AD 79-23-03 R1 Amdt 39-5282 also refers. Compliance: As per Requirement Document. Background: Evidence of corrosion in the interior of the steel spar in the subject tail rotor blades has been found. Amdt 1 limits applicability to those T.R. blades manufactured prior to the introduction of improved corrosion protection at manufacture.