AD/ERJ-170/21 Outboard Slat Skew Sensor (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-170/21 Outboard Slat Skew Sensor 4/2009

Applicability:

Model ERJ 170-100 STD, ERJ 170-100 LR, ERJ 170-100 SU, ERJ 170-100 SE,
ERJ 170-200 STD, ERJ 170-200 SU and ERJ 170-200 LR aircraft, equipped with the outboard slat skew sensor part number 1702286A or 1702288A.

Requirement:

Action in accordance with the requirements of ANAC AD 2009-02-02 Amdt
39-1260.

If an outboard slat skew sensor is found to be unserviceable, before further flight, replace it with a serviceable sensor.

Compliance:

Within 1,320 flight hours after 9 April 2009, unless already accomplished.  Repeat thereafter at intervals not to exceed 1,320 flight hours.

This Airworthiness Directive becomes effective on 9 April 2009.

Background:

There has been an occurrence of outboard slat skew sensor failure.  In combination with other possible faults, this may result in slat surface detachment from the wing, with the possibility of damage to the horizontal stabiliser and elevator, and could result in a loss of controllability.

David Villiers
Delegate of the Civil Aviation Safety Authority

24 February 2009