Releases Final Report on TransAsia Airways Flight GE 235 Occurrence Investigation
The Aviation Safety Council （ASC） releases final report on investigation of a TransAsia Airways （TNA） ATR72-212A （ATR72-600） aircraft, registration number B-22816, loss of control and crashed into Keelung River three nautical miles east of Songshan Airport.
On February 4, 2015, an ATR-GIE Avions de Transport Régional ATR72-212A （ATR72-600） aircraft, flight number GE 235, registered B-22816, took off from Songshan to Kinmen to execute a schedule transportation mission. There were 3 flight crews, 2 cabin crews and 53 passengers, total 58 people on board. The aircraft experienced a loss of control during initial climb and impacted Keelung River, three nautical miles east from its departing runway 10 of Taipei's Songshan Airport. Forty-three occupants were fatally injured, 15 occupants sustained serious/minor injuries. The aircraft's left wing tip collided with a taxi on an overpass before the aircraft entered the river. The taxi driver sustained serious injuries and the only taxi passenger sustained minor injuries.
According to Article 6 of the Republic of China （ROC） Aviation Occurrence Investigation Act, and the content of Annex 13 to the Convention on International Civil Aviation, the ASC, an independent aviation occurrence investigation agency, was responsible for conducting the investigation. The investigation team also included members from BEA （Bureau d'Enquêtes et d'Analyses, France）, TSB （Transportation Safety Board, Canada）, NTSB （National Transportation Safety Board, USA）, ATR （Avions de Transport Régional）, P&WC （Pratt & Whitney Canada）, UTAS （United Technologies Aerospace Systems）/USA, CAA Taiwan, and TNA.
The‘Draft Final Report’of the occurrence investigation was completed in January 2016. In accordance with the procedures, it was reviewed at ASC's 41th Council Meeting on January 26th, 2016 and then sent to relevant organizations and authorities for comments. After comments were collected and integrated, the English version Final Report was reviewed and approved by ASC's 44th Council Meeting on 26 April 2016. The Chinese version Final Report was reviewed and approved by ASC's 45th Council Meeting on 31 May 2016. Both versions of Final Report were published on 30 June 2016.
The accident was the result of many contributing factors which culminated in a stall-induced loss of control. During the initial climb after take-off, an intermittent discontinuity in engine number 2's auto feather unit （AFU） may have caused the automatic take-off power control system （ATPCS） sequence which resulted in the uncommanded autofeather of engine number 2 propeller. Following the uncommanded autofeather of engine number 2 propeller, the flight crew did not perform the documented abnormal and emergency procedures to identify the failure and implement the required corrective actions. This led the pilot flying （PF） to retard power of the operative engine number 1 and shut down it ultimately. The remaining altitude and time to impact were not enough to successfully restart the engine and recover the aircraft.
The investigation report identified a range of contributing and other safety factors relating to the engine's auto feather unit, crew of the aircraft, TransAsia's flight operations and management processes, and the regulatory oversight of TransAsia by the Civil Aeronautics Administration （CAA）.
There are a total of 25 findings from the Final Report, and 16 safety recommendations issued to the related organizations. （Please see the attachment 'GE235_Executive Summary' for more information）
Full investigation report is available for download at http://www.asc.gov.tw
All information published by press conference is also available to download from the following cloud drive.
Sherry Liu, Engineer