The captain of the Nok Air flight that slid off the runway at Chiang Rai airport will be asked to explain why passengers were kept on board for about an hour after the accident.
Suttipong Kongpool of the Civil Aviation Authority of Thailand (CAAT) said on Monday that the chief pilot of flight DD108 will be ordered to defend the decision.
The Don Mueang-Chiang Rai flight with 164 passengers and six crew slid off the runway as it landed in heavy rain at Mae Fah Luang on Saturday night. There were no injuries.
The captain turned off the engines after the accident, leaving the passenger cabin in darkness and without air conditioning.
The passengers were then told to stay on board until buses arranged by the airline arrived to take them to the terminal.
After about an hour fewer than 20 passengers had left by vans. The remaining passengers started complaining about the stuffy conditions in the cabin, the lack of fresh air causing breathing problems and the possible dangers of staying in their seats in the dark.
In a video taken by a passenger in the cabin, a woman crew member was heard trying to calm down the angry passengers and telling them to remain seated. She said, "Passengers are not allowed on runways."
The passengers insisted on leaving the plane and the captain eventually permitted one of the eight emergency exit doors to be opened so they could disembark on a slide.
"The captain is the one who makes the decision on evacuation after assessing the situation, including external factors," Mr Suttipong said.
Nok Air has also not explained the decision.
The airport remains closed until Wednesday, while the Boeing jet is removed and the runway examined for damage.
