AD/A109/49 - Battery Bus Circuit Breaker (Cth)

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

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 CASR 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.

Agusta A109 Series Helicopters

AD/A109/49 Battery Bus Circuit Breaker 3/2004

Applicability: A109E series helicopters as follows:

1. All serial numbers (S/N) up to and including 11077 that have kits part number 109-0812-04-101, or -103, or -107, or -109 installed, and

b. S/N 11078 up to and including 11122.

Requirement: Modify the emergency electrical bus in accordance with Agusta Mandatory Bollettino Tecnico 109EP-39 dated 25 November 2003.

Note: ENAC AD 2003-384 refers.

Compliance: No later than 31 March 2004.

This Airworthiness Directive becomes effective on 18 March 2004.

Background: The Italian Ente Nazionale per l'Aviazone Civile has advised that Agusta, whilst carrying out an investigation into the emergency busses of the A109E helicopter, discovered that in the event of a double generator failure the 25 Amp "BATT BUS" circuit breaker could trip. This Directive requires the modification of the emergency electrical bus installation by the replacement of the "BATT BUS" circuit breaker with a 35 Amp rated circuit breaker.