Voradej Harnprasert, Department of Civil Aviation director general, said the investigation was to find the causes of the accident and preventive measures, not to find fault or punish anyone.
He said reports from the Control Tower and the Airports of Thailand (AoT) on the malfunctioning right landing gear and sparks near the area of the landing gear were conflicting.
Conclusions from the preliminary investigation, together with the flight data recorder or black box, would be submitted to experts abroad for an in-depth probe, he said.
“We do not know how long the investigation will take. It takes years in some cases,” he said.
Sorajak Kasemsuvan, THAI president, said the damaged Airbus A330-300 aircraft would possibly be moved from the eastern runway by midnight.
A total of 172 arriving and departing flights at Suvarnabhumi Airport were delayed yesterday at 10-20 minutes on average.
The THAI aircraft arriving from Guangzhou skidded off the eastern runway Sunday night, injuring 13 passengers.