The black boxes recovered from the January 15 plane crash in Nepal are being sent to Singapore for analysis to identify the cause of the crash that killed all 72 people on board, officials said.

“The Nepal investigating team is leaving on Friday with the flight data recorder and cockpit voice recorder, where the data will be downloaded and analyzed,” said Civil Aviation Authority spokesperson Rajendra Kumar K.C.

It was initially suggested the black boxes be taken to France, where the aircraft was manufactured, but Nepalese authorities now plan to send the recorders to Singapore.

A committee formed by the government is still looking into the cause of the Yeti Airlines flight crash.

Rescuers are combing the hillside for the remains of two people still missing since the crash on Jan. 15 at the resort town of Pokhara, 200 kilometres (125 miles) west of the capital, Kathmandu.

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The twin-engine ATR 72-500 aircraft was approaching Pokhara International Airport in the Himalayan foothills when it plummeted into a gorge about 1.6 kilometres (1 mile) from the runway at an elevation of about 820 meters (2,700 feet).

While it’s still not clear what caused the crash, some aviation experts say video taken from the ground of the plane’s last moments indicated it went into a stall, although it’s unclear why.

It was carrying 68 passengers, including 15 foreign nationals, as well as four crew members. The foreigners included five Indians, four Russians, two South Koreans, and one each from Ireland, Australia, Argentina and France.

Nepal’s Civil Aviation Authority has also said the airport’s instrument landing system will not be working until February 26 - eight weeks after the airport began operations on January 1.

Aviation safety experts have said the absence reflects the poor air safety record in Nepal, where mountainous terrain and the resulting variable weather conditions make flying difficult.