Investigation Summary
The accident was initiated by a technical fault in the number 2 engine's Auto Feather Unit (AFU), likely caused by compromised solder joints. This resulted in an intermittent signal discontinuity that led the ATPCS to autofeather the right engine shortly after takeoff. However, the critical failure was the crew's response. The Pilot Flying (PF) reacted to the master warning by pulling back the throttle of the number 1 engine, stating, 'I will pull back engine one throttle.' Despite the Pilot Monitoring (PM) confirming a flameout on engine number 2, the PF continued to shut down engine number 1. This left the aircraft with no operative engines. The crew attempted a restart of the number 1 engine at low altitude, and while it did successfully restart, the aircraft had already entered a stall from which it could not recover. The final moments were captured by multiple dashboard cameras on a nearby viaduct, showing the ATR 72 banking sharply left, striking a taxi and the viaduct barrier before plunging into the river.
Final Conclusions
The Aviation Safety Council (ASC) concluded that the probable cause was a combination of mechanical failure and severe pilot error. The initial trigger was an intermittent signal discontinuity in the Auto Feather Unit (AFU) of engine 2, likely caused by compromised solder joints. Critically, the crew failed to reject the takeoff when the ATPCS ARM light did not illuminate during the takeoff roll, a violation of required safety checks. Following the engine 2 malfunction, the crew failed to follow standard operating procedures (SOPs) for engine failure, specifically failing to identify the malfunction before taking action. The Pilot Flying (PF) manually shut down the healthy engine 1, resulting in a total loss of power. The investigation also highlighted systemic issues at TransAsia Airways, including ineffective pilot training and a failure to ensure crews followed SOPs. The final report (ASC-AOR-16-06-001) was released in June 2016.
Photographic Evidence (1)
Video Analysis
Wrong Side | TransAsia Airways Flight 235 — A detailed breakdown of the pilot errors and mechanical faults that led to the crash of TransAsia 235 into the Keelung River.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Pilot Flying (PF)
Captain
Pilot Monitoring (PM)
Observer
Seated in cockpit jump seat
Systems & Failure Modes
ATPCS (Automatic Take-off Power Control System)
A system designed to automatically feather the propeller of a failing engine during takeoff to reduce drag. In this flight, it activated for engine 2 due to a faulty signal.
Auto Feather Unit (AFU)
The component responsible for detecting engine torque loss and triggering the feathering process. A hardware defect in the AFU for engine 2 initiated the accident sequence.
Stick Pusher
An automated system that pushes the control yoke forward to prevent a stall. It activated multiple times during the flight as the crew struggled to maintain airspeed.
Interesting Facts
- 01The aircraft was less than a year old, having been manufactured in 2014.
- 02The crash was captured on video by several automotive dashcams on the Huandong Viaduct.
- 03Fifteen people survived the crash, despite the aircraft coming to rest inverted in the river.
- 04The Captain had 4,914 total flight hours, with 3,401 on the ATR 72.
- 05The crew began reducing power to the functional left engine just 26 seconds after the initial master warning.
- 06The number 2 engine malfunction was caused by compromised soldering joints in the Auto Feather Unit.
Safety Actions & Advisories
ATR Pilot Proficiency Retesting
The Taiwanese CAA ordered all 71 TransAsia ATR pilots to undergo supplementary proficiency tests. Ten pilots failed the oral test and were suspended.
Airline Operations Shutdown
Following this accident and the earlier crash of Flight 222, TransAsia Airways suffered severe reputational damage and ceased all operations in November 2016.
Location
ACCIDENT SITE · Coordinates taken from the official investigation report.