Malaysia Airlines Mystery May Never Be Solved, Officials Say

April 2, 2014— -- Additional technology is being employed to search for missing Malaysia Airlines Flight 370, but officials admitted today that the mystery into the jetliner’s disappearance may never be solved.

“Investigations may go on and on and on. We have to clear every little thing," Malaysia Inspector General Khalid Abu Bakar told reporters in Kuala Lumpur. "At the end of the investigations, we may not even know the real cause. We may not even know the reason for this incident.”

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Probers hit another dead end today when the FBI completed its review of the pilot's at-home flight simulator looking for signs that the plane's maneuvers had been practiced or any other signs of preparation. But a senior U.S. official told ABC News there was "nothing suspicious whatsoever."

Malaysian officials spent hours meeting with the Chinese relatives of passengers on the doomed plane in Kuala Lumpur today, a meeting that one Malaysian official described as cordial. Prime Minister Najib Razak also planned to travel to Pearce Air Force Base to meet with the team running search operations off of Australia’s coast.

Flight 370 and its 239 passengers vanished on March 8 – 25 days ago – but the search continues to yield few answers. Search efforts for the Boeing 777 started over the Gulf of Thailand and South China Sea, then shifted west, north and south before settling on the southern Indian Ocean.

No trace of the plane has been recovered. The current search area is an 85,000-square-mile patch of ocean about 1,000 miles off of Australia’s coast.

Angus Houston, the head of a joint agency coordinating the multinational search effort out of Australia, said no time frame had been set for the search to end, but that a new approach would be needed if nothing showed up.

"Over time, if we don't find anything on the surface, we're going to have to think about what we do next, because clearly it's vitally important for the families, it's vitally important for the governments involved that we find this airplane," he told Australian Broadcasting Corp. radio.

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The search now includes a submarine, the British vessel HMS Tireless. Batteries on the plane’s black box pingers will start to fade in a handful of days, and the sub will have to be within a mile or so to hear them – a daunting possibility in a search area that’s roughly the size of Ireland.

“The luck with using submarines is that you’ve got to be in the right place,” said ABC News aviation analyst John Nance. “The water is only going to conduct it for a certain distance. We’re going to have to have a lot of luck to be in the right place.”

When the Malaysia Airlines plane’s black box batteries stop “pinging,” the search will focus more heavily on sonar scans of the ocean bottom. That tactic was used to find Air France Flight 447, which crashed into the Atlantic Ocean in 2009. It took two years to find the Air France jet.

Today’s search included 10 planes, including a Gulfstream G650 jet reportedly owned by movie director Peter Jackson.

The Associated Press contributed to this report.