AD/ERJ-170/4 Amdt 1 Flight Guidance Control Unit (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/ERJ-170/4 and issues the following AD under subregulation 39.001(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.

Embraer ERJ-170 Series Aeroplanes

AD/ERJ-170/4 Amdt 1 Flight Guidance Control Unit 12/2007 DM

Applicability:	ERJ-170(  ) model aeroplanes equipped with Primus EPIC software prior to load version 19.3.
Requirement:	1.    Carry out a functional test to check the engagement of the Flight Guidance Control System (FGCS) channels in accordance with Embraer Service Bulletin (SB) 170-22-0003, original issue, dated 9 November 2006 or further revisions approved by the Brazilian Agência Nacional de Avição Civil (ANAC).
Note 1:  For the purpose of this Directive, a functional check is defined as: "A quantitative check to determine if one or more functions of an item perform within specified limits.”
2.    Install the Primus EPIC software load version 19.3 or higher in accordance with Embraer SB 170-31-0019 original issue, dated 3 May 2007, or further revisions approved by the ANAC.
Note 2:  The installation of the Primus EPIC software load version 19.3 or higher is considered a terminating action for the Requirement 1 repetitive functional check.
Note 3:  ANAC AD 2006-11-02R1 Amdt 39-1212 refers.
Compliance:	For Requirement 1 - Within the next 300 hours time in service (TIS), after the first issue of an Australian Certificate of Airworthiness, and thereafter, at intervals that do not exceed 600 hours TIS until Requirement 2 is accomplished.
For Requirement 2 - No later than 30 June 2008.
This Amendment becomes effective on 19 October 2007.
Background:	The ANAC has received reports that some “caution” messages issued by the FGCS are not displayed on aircraft equipped with EPIC software load 17.3 or 17.5.  Therefore, following a possible failure on one FGCS channel during a given flight, such a failure condition will remain undetected or latent in subsequent flights.  If another failure occurs on the second FGCS channel, the result may be a command hard-over by the autopilot.

Since this condition may affect the safety of the aeroplane, the original issue of this Directive required the repetitive functional testing of the FGCS.

This Amendment continues the repetitive inspection requirement until software load version 19.3 or higher is installed.

The original issue of this Directive became effective on 4 April 2007.

David Punshon
Delegate of the Civil Aviation Safety Authority

10 October 2007