An official investigation led by the
Aviation Safety Council (ASC) of Taiwan was initiated. The aircraft's
flight recorders were recovered and read out. Some findings from the flight recorders were made known on 1 August 2014. It was revealed that the pilots announced an abort and go-around at 7:06 p.m., during final approach. At that time, the
RPM of the
number 1 (left pilot side) engine dropped, while unusual sounds were recorded by the
cockpit voice recorder. These sounds were considered to be consistent with a propeller churning on trees, an interpretation supported by the discovery of remnants of tree branches in one engine.
Typhoon Matmo Initially,
Typhoon Matmo was considered to be the cause of the crash, as Matmo had made
landfall earlier in the day. Taipei Center had prohibited pilots to fly, with Typhoon Matmo still above
Taiwan. The typhoon damaged buildings in Taiwan and injured 10 people. When Matmo had passed most of Taiwan, Taipei Center cleared pilots to fly in Taiwanese airspace, but it still warned pilots that the weather in and around
Penghu Island would remain inclement. The center of Matmo was only 23 nautical miles from Penghu Island. Infrared image from
Japan Meteorological Agency's satellite showed that the area surrounding Penghu were coloured "magenta" at 18:57, meaning that weather in Penghu was severe. Based on survivors' accounts, while approaching Penghu, the aircraft entered several instances of turbulence with thunder and lightning. At 19:00, Captain Lee told the passengers to prepare for landing, and the aircraft then crashed and exploded. Investigators interviewed the crew in the tower, who stated that the visibility in Magong had been greatly reduced due to Typhoon Matmo, although several minutes later, the visibility improved significantly. The investigation found that this was a
controlled flight into terrain accident. The crew had limited awareness of the aircraft's proximity to terrain. They continued the approach below the minimum descent altitude when they were not visually with the runway environment. The Captain was not complying with (and had a complete disregard for) policies, procedures and regulations. This type of hazardous attitude is characterized as "Anti-Authority". The final report reached the following final conclusion: ==Dramatization==