AD/ERJ-170/18 Electrical Wiring and ARINC 429 Data Bus (Cth)

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 39.001(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-170/18 Electrical Wiring and ARINC 429 Data Bus 12/2008

Applicability:

ERJ 170-100 STD, ERJ 170-100 LR, ERJ 170-100 SU, ERJ 170-100 SE,
ERJ 170-200 STD, ERJ 170-200 LR and ERJ 170-200 SU, with serial numbers (S/N) identified in Embraer Service Bulletins (SB) 170-24-0019 original issue, dated
20 July 2007, 170-24-0020 original issue, dated 30 November 2006, and 170-31-0020 original issue, dated 27 November 2007.

Requirement:

1.    Modify the electrical wiring on the overhead panel in the cockpit in accordance with SB 170-24-0019 original issue.

2.    Change the Air Data Smart Probe 3 channel B power supply bus from ESS2 to ESS3, in accordance with SB 170-24-0020 original issue.

3.    Duplicate the ARINC 429 airspeed signal for an extension longer than the rotor burst impact area; change the primary power source for MAU 2 from DC BUS 2 to DC ESS BUS 2; and, change the wiring of Slat/Flap Actuators Control Electronics (SF-ACE) 1 and 2 to Primary Actuator Control Electronics (P-ACE) 1, 2 and 3, in accordance with SB 170-31-0020 original issue.

Later revision of the above SBs, approved by the Brazilian Agência Nacional de Aviação Civil (ANAC), are acceptable for compliance with the relevant requirements of this Directive.

Note:  ANAC AD 2008-09-01 refers.

Compliance:

For Requirements 1, 2 and 3 - Within the next 6000 hours time in service after the effective date of this Directive.

This Airworthiness Directive becomes effective on 20 November 2008.

Background:

The ANAC has advised that a re-assessment of rotor burst analysis has shown the possibility of loss of electrical power supply to the following aircraft systems could result in loss of the aircraft pitch and yaw control:

Air data, ailerons, multifunctional spoilers and rudder.

Since the loss of aircraft pitch and yaw control affects flight safety, this Directive mandates corrective actions.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

29 September 2008