Commonwealth legislation

AD/S-76/71 - Rotor Brake Disc

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

7/10 complexity

This Airworthiness Directive requires operators of Sikorsky S‑76A/B/C helicopters to identify rotor brake discs by part and serial number, re‑mark certain Parker Hannifin discs, and inspect or replace discs with specific part numbers for cracking. The regulator’s delegate mandates compliance; operators bear the cost of inspections, marking (vibropeen) and any replacements. The directive uses serial‑number rules and visual/figure‑based crack criteria to decide whether a disc must be reidentified, remarking or removed from service.

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AIRWORTHINESS DIRECTIVE

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AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

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Sikorsky S- 76 Series Helicopters

AD/S-76/71 Rotor Brake Disc 4/2003 TX

Applicability: Model S - 76A, B, and C helicopters.

Requirement: 1. Determine the manufacturer of each rotor brake disc (RBD) by examining the part number (P/N) markings and accomplish the following requirements based on the identification of the RBD.

If the P/N is 76363-09101-102, the manufacturer is Goodyear. No further action is required by this directive.

b. If the P/N 76363-09103-102 is pressure stamped on the RBD, the manufacturer is BF Goodrich. No further action is required by this directive.

c. If the P/N 76363-09103-102 is electrolytically etched on the RBD, the manufacturer is Parker Hannifin Corporation (PHC).

For each PHC RBD with a P/N 76363-0913-102 and serial number (S/N) other than 38 through 379, remark the P/N as 76363-090103-105 using the vibropeen method. After remarking no further action is required.

ii. If the RBD serial number or the manufacturer cannot be determined and for RBD’s with P/N 76363-09103-102 and S/N’s 38 through 379, reidentify or mark the P/N as 76363-09103-104, or replace the RBD in accordance with requirement 3 of this directive.

2. For RBD’s with P/N 76363-0103-104, inspect the RBD for cracks as detailed in Figure 1.

If a crack is found extending through the entire RBD thickness as detailed in Figure 1, View A, replace the RBD with a serviceable RBD other than P/N 76363-09103-104.

b. If 2 or more surface cracks are found located between adjacent boltholes as shown in Figure 1, View B, replace the RBD with a serviceable RBD other than P/N 76363-09103-104.

Source text

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

AIRWORTHINESS DIRECTIVE AIRWORTHINESS DIRECTIVE

AIRWORTHINESS DIRECTIVE

Sikorsky S- 76 Series Helicopters