Commonwealth legislation

AD/BELL 412/25 - Main Rotor Flight Control System Bolts

RepealedCTH

This Act has been repealed and is no longer in force. It is retained for historical reference.

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

2/10 complexity

This is a mandatory safety directive (called an Airworthiness Directive) for owners and operators of Bell 412 series helicopters.

What it does: It requires inspection of the bolts in the main rotor flight control system — the critical components that connect the rotating controls allowing the pilot to steer the helicopter.

Why it matters: The manufacturer found some of these bolts were corroded, worn down, or damaged from rubbing (called "fretting"). If these bolts fail, the pilot could lose control of the main rotor, creating a serious risk of crash.

What must be done: Operators must follow the instructions in Bell Alert Service Bulletin No 412-89-45 to inspect these bolts. This inspection must happen at the next scheduled maintenance check after 20 August 1989, or by 20 October 1989 at the latest — whichever comes first. After that, the bolts must be reinspected every 24 months (2 years).

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Current sections

Direct links to the current provisions in AD/BELL 412/25 - Main Rotor Flight Control System Bolts.

AD/BELL 412/25 - Main Rotor Flight Control System Bolts

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

View image in the official source Bell Helicopter Textron 412 Series Helicopters

AD/BELL 412/25 Main Rotor Flight Control System Bolts 10/89

Applicability: All model 412 series.

Requirement: Action in accordance with Bell Alert Service Bulletin No 412-89-45. Compliance: At next scheduled inspection for issue of a Maintenance Release after 20 August

1989, or by 20 October 1989, whichever occurs first. Thereafter, reinspect at intervals not exceeding 24 months calendar time.

Background: Bell have advised that some of the rotating control bolts have been found corroded, fretting and/or with excessive wear on the bolt shank.

Source text

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