KUALA LUMPUR, Oct 3 — The Australian Transport Safety Bureau (ATSB) has expressed deep regret not being able to locate the missing Malaysia Airlines aircraft, flight MH370 with 239 people on board.

"We share your profound and prolonged grief, and deeply regret that we have not been able to locate the aircraft, nor those 239 souls on board that remain missing,” said ATSB which led the search mission in its 440-page final report released today.

It said the reasons for the loss of the Malaysian commercial aircraft could not be established with certainty until the aircraft, a Boeing 777, is found.

"It is almost inconceivable and certainly societally unacceptable in the modern aviation era with 10 million passengers boarding commercial aircraft every day, for a large commercial aircraft to be missing and for the world not to know with certainty what became of the aircraft and those on board,” the report said.

MH370 disappeared on March 8, 2014 during a scheduled flight from Kuala Lumpur to Beijing, sparking a large surface search in the initial stage and later extended for underwater search in the remote southern Indian Ocean which ended in January this year.

It was reported that the search costing US$200 million and funded by three countries – Malaysia, Australia and China – was officially suspended in January this year when traces of the Boeing 777 could not be found after a search of 120,000 sq km of the ocean.

The report said the understanding of where MH370 might be located, however, was better now than it had ever been.

"The underwater search has eliminated most of the high-probability areas yielded by reconstructing the aircraft’s flight path and the debris drift studies conducted in the past 12 months have identified the most likely area with increasing precision,” it said.

ATSB said debris from MH370 found on the shores of Indian Ocean islands and the east African coastline in 2015 and 2016 yielded significant new insights into how and where the aircraft ended its flight.

"It was established from the debris that the aircraft was not configured for a ditching at the end-of-flight,” the report said.

By studying the drift of the debris and combining these results with the analysis of the satellite communication data and the results of the surface and underwater searches, a specific area of the Indian Ocean was identified, which was more likely to be where the aircraft ended the flight, it added. — Bernama