COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters
AD/HU 369/48 Main Rotor Lead-Lag Bolts - Inspection
for Corrosion
Applicability: All model 369D and 369H series helicopters.
7/81
Requirement: In accordance with the procedures laid down in Section 7 of the applicable Basic H.M.I., inspect the inner bores of the lead-lag bolts for the presence of corrosion.
If corrosion is found, treat the bolts in accordance with the manufacturers instructions.
Compliance: Within 100 hours time in service after 31 July 1981, and thereafter at intervals not exceeding 300 hours time in service.
Background: There has been one local occurrence of failure of a lead- lag bolt on a model 369H helicopter. The failure is believed to be due to hydrogen embrittlement induced from a corrosion reaction inside the lower bore of the bolt. There is no inspection of the lead-lag bolts listed in the H.M.I. inspection schedules.