Australian investigators have said it is almost inconceivable for the world not to know with certainty what happened to flight MH370.
The Malaysian Airlines aircraft vanished in the southern Indian Ocean with 239 people on board in March 2014.
The Australian Transport Safety Bureau has issued its final report on the unsuccessful search operation.
The report concluded that the reasons for the loss of the aircraft could not be established with certainty until the aircraft was found.
The ATSB report also found that the captain of the plane had flown a route on his home flight simulator six weeks earlier that was "initially similar" to the one actually taken.
The aircraft was thought to have been diverted thousands of miles off course out over the southern Indian Ocean before crashing off the coast of Western Australia.
Australia, which led the underwater hunt, and Malaysia and China called off a A$200 million search for the plane in January, despite the protests of families of those onboard.
Six weeks before the aircraft's disappearance, Captain Zaharie Ahmad Shah used his home simulator to fly a route that was initially similar to part of the route flown by MH370 up the Strait of Malacca, with a left-hand turn and track into the southern Indian Ocean, the ATSB said in its report.
The report said: "By the last data point the aircraft had flown approximately 4,200 nautical miles.
"This was further than was possible with the fuel loaded on board the aircraft for flight MH370."
The simulated aircraft track was also inconsistent with those modeled using satellite signal data from MH370, the report said.
However, the ATSB said there were enough similarities to the flight path of MH370 for the agency to carefully consider the possible implications for the underwater search area, including whether it glided after fuel exhaustion or was ditched in a controlled manner.
Aircraft debris found later indicated the flaps were most likely retracted, which was not consistent with a controlled ditching, the report said.
Australia's main scientific agency said last August it believes with "unprecedented precision and certainty" that the plane crashed northeast of the search zone.
But those findings were dismissed by Australia's government at the time as not specific enough, and the search has not been re-opened.
Doing so depends on finding credible, new evidence about the plane's whereabouts.
The ATSB report detailed the unsuccessful 1,046-day hunt for the plane, above and below the surface of the Indian Ocean, and scientific analyses of satellite pictures, sea currents and even barnacles found clinging to a piece of the plane found on Reunion Island.
"The understanding of where MH370 may be located is better now than it has ever been. The underwater search has eliminated most of the high probability areas," the ATSB said.
"We...deeply regret that we have not been able to locate the aircraft, nor those 239 souls on board that remain missing."
