A Cambodian delegation will carry the flight data recorder from a plane that crashed last week to Russia, authorities said Monday.
Aviation officials hope the "black box" will reveal more about how PMT Flight U4 241 crashed a week ago in rainy, coastal mountains.
Twenty-two died in the crash, the worst air fatality since 1997, when a Vietnam Airlines flight crash killed more than 60.
Though an official cause of the crash has not been announced, a number of officials have said they suspect poor weather. The company running the flight, however, has a spotty safety record, as does the plane that crashed, a Russian-made Antonov.
Civilian Aviation Secretariat Director Him Sarun said the cause of the crash will remain unknown until the data recorder is analyzed.
"No one can answer the question, until after the black box is analyzed," he said. "Otherwise, whatever people say is pure speculation. Please don't believe it. It is only a guess. The black box is the only thing that can analyze everything."