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 12/41 Tail Rotor Blades 9/90 TX
Applicability: All models UH-12E, UH-12E-L, UH-12L and UH-12L4 helicopters.
Requirement: Visually inspect tail rotor blades P/N 55073 and remove from service tail rotor blade assemblies with serial numbers 3028, 3089, 9506, 9584, 9607, 10245, 10516, 10917,
13278, 14715, 14898, 15073, 15285, 15978, 16114, 20918.
Unairworthy blades found are to be permanently marked unserviceable and reported to the Authority.
Note: FAA Telex AD 90-15-01 refers.
Compliance: Unless already accomplished, prior to further flight after 19 July 1990.
Background: Country of origin AD. It has been found that records for certain life limited tail rotor blades have been falsified. Service life limits may have been exceeded, this could result in blade failure and loss of control of the helicopter.