A twin engined ATR 72-600 turboprop suffered an engine failure shortly after takeoff from Taipei Songshan Airport, destination the Kinmen islands. The plane, which was less than one year old according to Flightglobal crashed into the Keelung river. The number of survivors is uncertain at this time.
The plane which crashed into a river in Taiwan at about 02:55 GMT was successfully craned out by about 13:00 GMT. The incredibly swift reaction of the various organisations responsible for rescue and recovery is exemplary. The task of forensic investigators will be made easier thanks to the skill and professionalism of the recovery teams. In forensic science the preservation of evidence is vital. Live video shows that the best care is being taken under all the circumstances.
Footage from a dashcam shows that the plane dropped its left wing, the tip of which struck a taxi. The wingtip then struck a safety rail on the elevated highway and the plane dropped into the Keelung river. The taxi driver was able to stop his vehicle safely and exit.
Taxi struck by wingtip
Forensic science in action
The general public depends on scientists and engineers to discover what went wrong when trains, planes, automobiles etc. crash. In this day and age cameras abound. When an incident like this occurs the combination of images, wreckage and FDR data can lead to very precise determination of the causes of a crash for the avoidance of repetition. The same evidence can be used to improve survivability in future incidents. Anyone whose life was saved by airbag, seat belt, crumple zone etc. should pause to thank forensic scientists.
ATR 72 crash caught on dashboard camera.
images copyright MISSXOXO168
These still images, together with the image of the taxi, the reported Mayday - engine flameout, the location and aviation/engineering background knowledge point to the following plausible scenario.
The pilot commenced a turn to the right after a westward take-off, intending to fly east. At some point in that turn the left engine flamed out. The immediate effect of that engine loss would be a tendency to first yaw left and then reduce right bank angle. The auto-feathering device works by detecting torque reversal - when the prop is trying to spin the engine. This takes time: meanwhile the plane begins to lose speed and/or altitude.
It is, in the authors opinion, highly likely that the pilot knew that he had no time to take all the actions needed to gain height. Faced with unavoidable descent he intended to set down in the river. His chosen path was highly risky, but any failed alternative was likely to end in a crash into blocks of flats in the densely populated city. This crash could be the outcome of a heroic effort to save the lives of people on the ground at all costs.
The speed with which rescuers reached the crash scene and saved lives is an example to the world. Not only did rescuers pull people from the water: they also tore open the fuselage to get people out. Further: they rigged nets downstream to trap bodies and wreckage which might otherwise have floated away.
These professionals have provided a lesson in recovery and forensic evidence preservation. The plane was first hauled nose-first into a floating landing stage. Other pontoons were brought to the scene to stabilize the fuselage. Floodlights and a crane were rapidly brough to the site. As the lift began the salvagers paused the lift to allow water to drain out. That is a vital operation: trapped water can cause a sudden increase in load on the crane, leading to broken strops or a toppled crane.
Water drains from the fuselage
screenshot from TVBS live feed
It was obvious that the remains of the composite tail fin would not support any load, so a digger was used to make a trench in the river bank to accomodate it.
Tail fin detail
Fuselage recovered
The greater part of the wreckage and the black boxes were recovered in conditions of darkness. The local air temperature was a chilly 14 deg C at best, and doubtless the water was much colder. The wind was a breezy 6mph and the river current was probably between 4 and 6 knots. Those are not pleasant conditions for recovery work, which makes this incredibly rapid recovery effort even more praiseworthy. It is to be hoped that the official report will heap praise on these fine professionals.
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