The 40-year-old co-pilot was conducting his preflight check on Eastar Jet Flight ZE532 when he started suffering breathing difficulty and fell unconscious, said Lt Suporn Muangkhai of the Thalang Police.
The Boeing 737-800, scheduled for takeoff at 3:20am, was carrying 180 passengers and six crew, bound for Incheon International Airport in Seoul, South Korea.
“Airport emergency responders transported him to Thalang Hospital, where he was later pronounced dead,” said Lt Suporn.
“Staff at the hospital emergency room reported the death at 8:20am,” he added.
“Doctors at Thalang Hospital confirmed that the man died of heart attack. No signs of assault or injury were found on the body.
“We are contacting the South Korean Embassy so they can notify his family,” he said.
The flight has been rescheduled to takeoff at 1:40pm today.
A tour handler in Phuket for Eastar Jet confirmed to The Phuket News at 1:20pm today that the passengers had boarded the aircraft.
“The are no issues with the aircraft. The flight is about to take off now,” she said.