Behind the mystery of Malaysia Airlines Flight MH370

A new report Sunday provides some details on the disappearance of Malaysia Airlines Flight MH370 one year ago. But how and why it happened with 239 people aboard remains a mystery.

It may be the greatest aviation mystery since Amelia Earhart disappeared over the Pacific in 1937 trying to circumnavigate the globe.

The big difference, of course, was in lives lost. Ms. Earhart and her navigator Fred Noonan were the only ones aboard her Lockheed Electra 10E twin-propeller aircraft. Malaysia Airlines Flight MH370, lost a year ago on a flight from Kuala Lumpur to Beijing, was a Boeing 777 wide-body jet carrying 227 passengers and 12 crew members.

There are other differences as well. Earhart’s flight came during the run-up to war in the Pacific, with US and Japanese intelligence agencies learning all they could about a vast expanse of ocean dotted with island and atolls that might one day prove strategically significant – an intelligence effort some believe Earhart was part of. Also, the means of communication and navigation were far less sophisticated and reliable 78 years ago than those aboard MH370. No pinging devices to guide searchers, for example.

As it turns out, the battery on one of those devices on MH370 – the one for the locator beacon on the plane's flight data recorder – had expired more than a year before the jet vanished on March 8, 2014. A computer error meant maintenance crews didn’t know it was time for a new battery. That’s one of the revelations in an interim report released Sunday.

Although the battery for the locator beacon in the other “black box” – the cockpit voice recorder – was working, a weaker or nonexistent “pinger” in one of the devices could have made it more difficult for searchers aboard ships and aircraft scouring tens of thousands of square miles.

The report also finds nothing suspicious about the flight crew.

"There were no behavioral signs of social isolation, change in habits or interest, self-neglect, drug or alcohol abuse of the Captain, First Officer and the Cabin Crew," the report states. "On studying the Captain's behavioral pattern on [closed circuit television] recordings on the day of the flight and prior 3 flights there was no significant behavioral changes observed. On all the CCTV recordings the appearance was similar, i.e. well groomed and attired. The gait, posture, facial expressions and mannerism were his normal characteristics."

The report also notes that 487 pounds of lithium ion batteries packed by Motorola Solutions in Malaysia's Penang state didn't go through security screening at Penang airport. The shipment was inspected physically by the airline cargo personnel and went through customs inspection and clearance before it was sealed and left Penang a day before the flight. At the Kuala Lumpur airport, it was loaded onto the plane without any additional security screening.

The report said the batteries were not regulated as dangerous goods. There were 99 shipments of lithium ion batteries on Malaysia Airlines flights to Beijing from January to May last year.

Among the most pertinent unanswered questions: Why Flight MH370 flew so far off course without giving any indication of cause or purpose before it finally disappeared from radar scopes in the region. Some analysts looking at all the available information have concluded that it must have been deliberate. Conspiracy theories abound.

In Sydney on Sunday, Australian Prime Minister Tony Abbott conceded that the search “can’t go on forever.”

“But as long as there are reasonable leads, the search will go on," Mr. Abbott told reporters. "We've got 60,000 square kilometers that is the subject of this search. If that's unsuccessful, there's another 60,000 square kilometers that we intend to search and, as I said, we are reasonably confident of finding the plane."