|Title:||Uncommanded roll, Serious incident on March 20, 2001 at Frankfurt/Main, to Airbus Industrie A320-200 (Recommended)|
|Micro summary:||This A320 experienced an uncommanded roll to the left.|
|Publishing Agency:||Federal Bureau of Aircraft Accidents Investigation (BFU)|
|Site of event:||Takeoff, Frankfurt/Main|
|Airplane Type(s):||Airbus A320-200|
|Type of flight:||Revenue|
|Executive Summary:||An Airbus A 320 had departed at 11:00 hrs UTC from runway 18 for a flight to Paris. 115 passengers and 6 crew members were aboard the aeroplane. Immediately following the lift-off the aeroplane assumed a slight bank angle to the left. The commander, who was the pilot flying, tried to correct the attitude by a slight input on the left sidestick. However, the bank angle increased continuously up to approx. 22°. With the commander’s call out :“I can’t do anything more“ the first officer took over the controls with the words “I have control“ and pressed the TAKE OVER PUSH BUTTON. The First Officer had already beforehand instinctively tried to counteract the rolling movement with his sidestick.|
Controlled by the second autopilot the aeroplane climbed to flight level FL 120 where the crew cautiously analysed the control system. With an input on the left sidestick the aeroplane - after a short shaking and a brief bank angle corresponding to the input - suddenly reacted contrary. The right-hand sidestick functioned normally.
The crew decided to not continue the flight but to return to Frankfurt. The First Officer took over the controls and safely landed the aeroplane in Frankfurt. The aeroplane was than handed over to the maintenance organisation.
Prior to this flight, the aeroplane had already been at the maintenance organisation for two days for repair purposes. On several previously conducted flights had problems occured on one of the two elevator aileron computers (ELAC), which control, among other things, the bank angle. When the computer was replaced, a bent pin, which could not be repaired, was found on the plug of the ELAC no. 1. Therefore the whole plug of the ELAC no. 1 was replaced and rewired. Two pairs of wires were connected inverted, the Command Channel and the Monitor Channel.
The BFU has come to the conclusion that the serious incident is due to the fact that:
• during repair work on the plug of the Elevator Aileron Computer (ELAC) no. 1 two pairs of wires had been connected inverted
• the error remained undetected
• the error was not recognized by the flight crew during the “FLIGHT CONTROL CHECK“.
Contributing factors were:
• an unclear and difficult to handle documentation so that a wrong wiring diagram was used
• diversion from the manufacturer’s data by the Maintenance Support
|Learning Keywords:||Operations - Maintenance|
|Operations - Upset - Uncommanded or excessive Roll|
|Systems - Flight Control System|
|Close match:||Excessive right aileron required on Boeing 737-400, EI-BXB, at Dublin Airport|
|Uncommanded roll, Boeing 737-236 Advanced, G-BGJI|
|Flight control system failure, Report on the incident to Airbus A320-212, G-KMAM, London Gatwick Airport, on 26 August 1993|
|Aileron control cable failure on a Boeing 737-3TO on takeoff at Seattle, September 27, 1997|
|Uncommanded roll to the left, Boeing 737-3B7, August 5, 1995|
|Uncommanded roll, Douglas DC-8-71F, December 14, 2001|
|Uncommanded roll, McDonnell Douglas DC-9-15, July 12, 1997|
|Uncommanded roll during cruise, Airbus A320-211, April 28, 1995|
|Uncommanded roll and yaw, Douglas DC-9-34, April 30, 1998|
|Control difficulties, McDonnell Douglas MD-11, October 21, 1998|
|Reduced roll capability, Boeing 747-422, April 1, 2003|
|Roll control difficulties, McDonnell Douglas MD-11F, N583FE, January 15, 2003|
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