Commonwealth legislation

AD/AS 355/31 - Tail Rotor Gearbox Casing

RepealedCTH

This Act has been repealed and is no longer in force. It is retained for historical reference.

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Commonwealth

Collection

legislative instrument

Plain English Summary

2/10 complexity

This directive requires owners/operators of Eurocopter AS 355 helicopters to perform repeated inspections of the tail rotor gearbox casing for cracks and to carry out a permanent modification per the manufacturer’s Service Bulletin No. 05.18. Inspections are every 50 flight hours until the AMS 350A07-8535 modification is done, then every 400 hours. The modification must be completed by 1,100 total hours or within 100 hours after Nov 18, 1987, whichever is later.

It addresses cracks in the blade-horn support yoke radius that could cause loss of tail-rotor control.

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AD/AS 355/31 - Tail Rotor Gearbox Casing

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Eurocopter AS 355 (Twin Ecureuil) Series Helicopters

AD/AS 355/31 Tail Rotor Gearbox Casing 1/88

Applicability: All model AS 355 Series helicopters.

Requirement: 1. Inspect the tail rotor gearbox casing in accordance with Para 1C(2) of SB No 05.18.

Inspect and modify the tail rotor gearbox in accordance with Para 1C(3) of SB No 05.18.

Compliance: For Para 1: Within 50 hours time in service after 18 November 1987 and thereafter at intervals not exceeding 50 hours time in service, until modification AMS 350A07- 8535 (polishing blend radii) is incorporated. After modification, inspect at intervals not exceeding 400 hours time in service.

For Para 2: Prior to exceeding 1100 hours total time in service or within 100 hours time in service after 18 November 1987, whichever is the later.

Background: The manufacturer has received reports of cracking in the blade horn support yoke radius just inboard of where the tail rotor control bellcrank pivot bolt is located.

Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

1 AD/AS 355/31 - Tail Rotor Gearbox Casing