Commonwealth legislation

AD/AS 355/71 Amdt 1 - Electrical Power System

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

5/10 complexity

This directive addresses repeated electrical-generator failures on AS 355 helicopters by limiting landing-light use to take-off and landing unless a hardware retrofit is installed. Operators must either follow the operational restriction and placard immediately or complete a specified modification—replacing non-temperature-compensated contactors with temperature-compensated circuit breakers per ASB No. 24.00.14 (or Revision 1)—by 1 December 2003. Once the retrofit is embodied the AFM revision and placard can be removed.

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Current sections

Direct links to the current provisions in AD/AS 355/71 Amdt 1 - Electrical Power System.

Do not use the landing light outside the

Do not use the landing light outside the landing and take-off phases

3. Replace the non temperature-compensated contactors with temperature- compensated circuit breakers, in compliance with the instructions described in either ASB No. 24.00.14 or ASB 24.00.14 Revision 1 (corresponds to MOD 073019).

Following embodiment of this modification the Requirement 1 AFM revisions and the Requirement 2 placard may be removed.

Note 2: DGAC AD 2000-339-060(A) R3 refers.

Compliance: For Requirements 1 & 2 - As of the effective date of this Directive.

For Requirement 3 - Before 1 December 2003.

This Amendment becomes effective on 30 October 2003.

Background: AD/AS 355/55 was issued following several reports of complete loss of the electrical power generating systems, except for the direct battery power, on AS 355 helicopters. The failures occurred at a high outside air temperature (above 25°C) during long duration flights (more than one hour with landing light on).

AD/AS 355/55 required an AFM revision, which limits the landing light operation to take-off and landing and introduces emergency procedures for loss of the electrical power generating systems. The Directive also required a placard to be fitted advising the pilot of the landing light operational limitation.

The original issue of this Directive superseded the earlier AD, limited applicability to helicopters equipped for IFR flights, extended applicability to cover electrical master boxes with all part numbers and introduced a terminating action.

Source text

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

Do not use the landing light outside the Do not use the landing light outside the landing and take-off phases