On the first flight following a maintenance check, the aircraft experienced an uncommanded yaw resulting in a roll to the left as it accelerated through 185 kt. Directional control was regained and subsequent cockpit indications identified a fault with the rudder Travel Limitation Unit (TLU). The aircraft returned to Edinburgh Airport, where it landed safely. The investigation into this serious incident was conducted in conjunction with the Air Accident Investigation Unit (AAIU) of Ireland and the ‘Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile’ (BEA) of France. The investigation established that a cam on the rudder TLU mechanism had been removed and incorrectly refitted during the maintenance check. As a result of this incident AAIB Special Bulletin S1/2011, containing three Safety Recommendations, was published on 15 April 2011. Since this incident the aircraft manufacturer and the engineering organisation have taken safety actions to minimise the possibility of a similar event recurring. Two further Safety Recommendations are made in this final report.
ATR72-202 EI-SLG 07-12.pdf (9,734.11 kb)