Commonwealth legislation

AD/AS 355/33 Amdt 1 - Tail Rotor Front Drive Shaft

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

This airworthiness directive requires operators of Eurocopter AS 355 helicopters fitted with forward drive shaft P/N 355A34-1037-00 to follow Aerospatiale Service Bulletin No 05-20 Rev 2. It imposes an initial inspection within a short hours-or-date window, recurring inspections at set intervals, and inspections tied to removal/installation or evidence of vibration or cracking. The Civil Aviation Safety Authority mandates compliance; operators pay for the additional inspections and must change maintenance scheduling to address a risk from an unbalanced oil‑cooler fan assembly.

JSON API

Deep dive

Want the full deep dive?

Zoe can write the in-depth analysis on top of the summary above: how it works, who it affects and what each part actually does.

Current sections

Direct links to the current provisions in AD/AS 355/33 Amdt 1 - Tail Rotor Front Drive Shaft.

AD/AS 355/33 Amdt 1 - Tail Rotor Front Drive Shaft

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

View image in the official source
Eurocopter AS 355 (Twin Ecureuil) Series Helicopters

AD/AS 355/33

Amdt 1

Tail Rotor Front Drive Shaft 5/89

Applicability: All model AS 355 fitted with forward drive shaft P/N 355A34-1037-00. Requirement: Action in accordance with Aerospatiale Service Bulletin No 05-20 Revision 2.

Compliance: 1. Within 50 hours TIS after 7 December 1988 or by 31 December 1988, whichever occurs first. Thereafter, reinspect at intervals not exceeding 100 hours time in service.

2. Before removal and after installation of the following components:

\- forward drive shaft elements,

\- oil cooler,

\- fan,

\- oil cooler or fan support.

3. If abnormal vibration is noted in the fan assembly,

4. If a crack is found on one of the oil cooler or fan supports.

Background: The manufacturer has advised of a forward drive shaft failure caused by excessive unbalance of a main gearbox oil cooler fan assembly. A further revision of the requirement document requires the compliance requirements to be expanded.

Source text

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

1 AD/AS 355/33 Amdt 1 - Tail Rotor Front Drive Shaft