TAIPEI - The pilots of a TransAsia Airways plane that crashed in July killing 48 people could not see the runway as they descended to the ground during a rainstorm, Taiwanese authorities said Friday.
Flight GE222 carrying 54 passengers and four crew crashed on July 23 near the airport in Magong in the Penghu islands, a scenic island group in the Taiwan Strait, leaving just 10 survivors. Two French nationals were among the dead.
The ATR 72-500 propeller plane deviated off course before plunging into civilian houses after an aborted landing during thunder and heavy rain as Typhoon Matmo pounded Taiwan, officials have said.
"The plane was flying lower and lower and was deviating left," said Thomas Wang, director of the Aviation Safety Council, during the release of a report on the incident.
According to transcripts of the plane's two black boxes, which record voices in the cockpit and other in-flight data, the co-pilot twice replied "no" when asked by the pilot whether he had seen the runway.
The exchange occurred when the plane was at a height of less than 200 feet (60 metres). Less than 20 seconds later, the recording stopped.
Wang said that when a plane descends to 330 feet, it is required to maintain that altitude until pilots can see the runway.
"But it did not maintain 330 feet and continued to descend," he said. "This is a fact. But why it continued to descend we cannot say at the moment." The Aviation Safety Council will consult with experts from Canada, France and the United States before releasing a draft report on the cause of the crash around June 2015, and a final report in October, he added.
The council said in August when it unveiled initial findings from the black boxes that no distress call was recorded.
It said two unidentified sounds were recorded, which were likely the sounds of the plane colliding with woods about one kilometre from the airport before plunging into the ground.
Angry relatives have blamed the authorities and TransAsia for the worst air disaster in a decade in Taiwan, questioning why the plane was cleared to take off in stormy weather.
Taiwanese officials have defended the decision to allow the flight to go ahead, saying meteorological data showed that aviation safety requirements were met when the plane was cleared to fly.