COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Hiller UH-12 Series Helicopters AD/HILLER 12/30 Amdt 2 Main Rotor Assembly 8/86 Applicability: All models UH-12D, UH-12E, UH-12E4, OH-23F, OH-23G and all models converted by STC SH 178WE and STC SH 177 WE equipped with main rotor blades assembly Parsons P/No. 2253-1101. Requirement: Action in accordance with Rogerson Hiller SB UH12-51-6 Revision dated 19 December 1985. Note: FAA AD 80-14-12 Amdt 39-3836 refers. Compliance: As per Requirement Document. Note: The Daily Inspection may be accomplished by the pilot in command, in which case an entry and certification for this AD shall be made in Col. 2 Part 3 of the Maintenance Release on each occasion. Background: The main rotor blade spar may develop bond separation and voids leading to spar cracking. This Amendment introduces a daily visual inspection, reduces the dye penetrant inspection period from 100 hours' time in service to 25 hours' time in service, adds a bond separation and void inspection by "coin tapping" and specifies an overhaul requirement.