AD/A320/166 Elevator and Aileron Computer (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.

Airbus Industrie A319, A320 and A321 Series Aeroplanes

AD/A320/166 Elevator and Aileron Computer 3/2005 TX

Applicability:

A320 all certified models, all manufactured serial numbers, except aircraft that have incorporated Airbus modification 33317 during production or Airbus Service Bulletin A320-27-1149 whilst in service.

Requirement:

Amend the Minimum Equipment List (MEL) by inserting Temporary Revision (TR) TR No 01-27/01H issue 01 of the Master Minimum Equipment List (MMEL) A318/A319/A320/A321 that introduces the operational limitation “Above FL 200, the use of speed brakes lever is limited to its half position” when the aircraft is under MMEL ELAC 1.

Later revisions of the above document approved by the DGAC are acceptable for compliance with this Directive.

Note:  DGAC AD F-2005-013 (EASA Approval 2005-496) refers.

Compliance:

Before 31 January 2005.

This Airworthiness Directive becomes effective on 28 January 2005.

Background:

The Direction Générale de l’Aviation Civile of France has advised that during investigations on an A320 aeroplane the following critical flight phase was evident:

When the aircraft is under MMEL with ELAC 1 (Elevator and Aileron Computer) inoperative or ELAC 1 PITCH FAULT cautions displayed, the loss of SEC 1 (Spoiler and Elevator Computer) in descent when speed brakes are deflected will lead to:

-     the automatic retraction of speed brakes 3 and 4,

-     the loss of the double hydraulic pressurisation on elevators.

In manual mode and at high speed, the retraction of speed brakes 3 and 4 from their full extended position will induce a pitch down effect that cannot be counteracted by the elevator controlled by a single actuator causing the aircraft to pitch down and accelerate.

This Directive requires the amendment of the MEL to ensure the aeroplane remains under control.

James Coyne
Delegate of the Civil Aviation Safety Authority

25 January 2005