The pilot of a passenger plane that crashed in Taiwan killing 43 people shut down the aircraft's only working engine, exclaiming: "Wow, pulled back wrong throttle," seconds before the disaster, investigators said Thursday.
TransAsia Airways Flight GE235 clipped a bridge and plunged into a river shortly after take-off from Taipei's Songshan airport in February with 53 passengers and five crew on board. Only 15 people survived.
Disturbing cockpit transcripts released by Taiwan's Aviation Safety Council revealed the pilots trying to deal with an engine that had lost power, but then reducing the thrust of the other, functioning engine.
Thursday's report said the plane climbed to 1,200 feet (365 metres) before a warning alarm sounded, which indicated that the plane's second engine had undergone "flameout at take off".
Despite the warning signal coming from Engine Two, the pilot at the controls said: "I will pull back Engine One throttle."
Chaos then ensued with both engines failing as the pilots tried to restart them in the few seconds before the crash.
The last words from the black box recordings were the monitoring pilot shouting: "Impact, impact, brace for impact."
Dramatic car dashcam images at the time showed the plane hitting an elevated road as it banked steeply away from buildings before crashing into the Keelung River.
"As the pilot pulled back the wrong throttle, for some time both engines were powerless," said Thomas Wang, head of the aviation council.
Wang also confirmed previous reports that the pilot had failed a simulator test for engine failure on take-off last year, but passed a later retake.
Investigators refused to name the pilot at the controls but reports at the time of the crash identified him as Liao Chien-tsung.
Initially Liao was hailed as a hero for steering the plane away from houses and into the river as it came hurtling down.
Liao's distraught parents defended their son following the release of the report.
"At the end of the day, my son is dead, either as a 'hero' or being blamed (for the incident) is meaningless to us now," Liao's father Liao Hsien-ming, told the United Evening News.
He added that he still felt proud of his son saying he had tried to reduce casualties on the ground in the final seconds before the crash, as the plane dodged buildings to plunge into the river.
"Why the pilot did this, we don't know. That's the main task for our (final) analysis report," said Wang over the decision to pull back the throttle on Engine One.
The draft of that report is due out in November with the final version expected in April 2016.
Thursday's evidence was described as a "factual report" giving more detail about the crash, but not attributing responsibility or drawing final conclusions about the cause.
TransAsia officials did not comment on the findings at a press conference Thursday but said that following the crash they had stepped up pilot training and brought in new safety experts, local media reported.
Taiwan's aviation regulator ordered TransAsia pilots to take an oral test on basic operating and emergency procedures for the French-made aircraft after the initial findings pointed to pilot error.