COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

Bell Helicopter Textron 412 Series Helicopters

AD/BELL 412/10 Upper Anti-Collision Strobe Light P/No HR,

DF-28DRMS Inspection, Modification and Replacement

Applicability: All 412 models fitted with subject anti-collision strobe light.

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Requirement: 1. Inspect upper anticollision strobe light per Bell Alert Service Bulletin No. 412-83- 14.

2.    Modify upper anti-collision strobe light per Bell Alert Service Bulletin No. 412- 83-14.

3.    Replace upper anti-collision strobe light with P/No. 70285-01 Assembly (Whelen).

Compliance: For para 1. Before further flight after 24 November 1983 and thereafter at intervals not exceeding 25 hours time in service.

For para 2. Before 31 December 1983.

For para 3. Before 1 March 1983.

Background: Separation of the cup shaped lower portion of the light assembly which contains power supply components has occurred. These components have consequently contacted the main drive shaft resulting in minor damage. A potential problem exists in the retention of the entire light assembly, failure of which could cause similar damage.