How can a plane disappear?

How can a plane carrying 239 people just disappear over the ocean for more than three days?

As puzzling as it sounds in this age of modern technology, what happened to Malaysia Airlines flight MH370 is not the first reminder of how vast the seas are and how difficult it is to locate something lost in them, said a report by the AP news agency.

It took two years to find the main wreckage of an Air France jet that plunged into the Atlantic Ocean in 2009.

It also took a week for debris from an Indonesian jet to be spotted in 2007 after it crashed near the area between Malaysia and Vietnam where Saturday's flight vanished. Today, the mostly intact fuselage still sits on the bottom of the ocean.

"The world is a big place," Michael Smart, professor of aerospace engineering at the University of Queensland in Australia, told AP. "If it happens to come down in the middle of the ocean and it's not near a shipping lane or something, who knows how long it could take them to find?"

To add to the confusion, officials had said that MH370 might have made a turn back towards Kuala Lumpur, making it even more difficult to find as it might have been hundreds of kilometres from where it last made contact with air traffic controllers.

Aviation experts say the plane will be found — eventually. Since the start of the jet age in 1958, only a handful of jets have gone missing and not been found, the AP report said.

"I'm absolutely confident that we will find this airplane," Captain John M. Cox, who spent 25 years flying for US Airways and is now CEO of Safety Operating Systems, was quoted as saying.

With modern communications technology and GPS features in our cars and smartphones, many of us have set set unreal expectations, the report said.

"This is not the first time we have had to wait a few days to find the wreckage," Captain Cox told AP.

Based on what he's heard, Captain Cox believes it's increasingly clear that the plane somehow veered from its normal flight path.

He said that after the plane disappeared from radar, it must have been "intact and flew for some period of time. Beyond that, it's all speculation."

If it had exploded midair along its normal flight path, "we would have found it by now."

Department of Civil Aviation (DCA) director-general Datuk Azharuddin Abdul Razak had said that more than 1,000 people and at least 34 planes and 40 ships were searching a radius of 185 kilometres around the last known location of Flight MH370.

No signal has been detected since early on Saturday morning, when the plane was at its cruising altitude and showed no sign of trouble.

Azharuddin had said the search included the northern parts of the Straits of Malacca, on the opposite side of the plane's last known location. However when pressed by reporters on why the search is being conducted there, Azharuddin had merely said: "There are some things that I can tell you and some things that I can't."

The AP report said some aviation experts are already calling for airlines to update their cockpit technology to provide a constant stream of data – via satellites – back to the ground. Information about key system operations is already recorded on the flight data and voice recorders – the so-called black boxes – but as this crash shows, the data is not immediately available.

Just about every major jet to disappear in the modern era has eventually been found. The rare exceptions didn't involve passengers.

In September 1990, a Boeing 727 owned by Faucett Airlines of Peru was ditched into the North Atlantic after running out of fuel on its way to Miami. The accident was attributed to poor pilot planning and the wreck was never recovered.

More mysterious was the disappearance of another 727 in Africa. It was being used to transport diesel fuel to diamond mines. The owners had numerous financial problems and one day, just before sunset, the plane took off without clearance and with its transponder turned off. It is believed to have crashed in the Atlantic Ocean. One theory, never proven, is that it was stolen so the owner could collect insurance.

"I can't think of a water crash in the jet age that hasn't been solved ," the AP report quoted Scott Hamilton, managing director of aviation consultancy Leeham Co, as saying. – March 11, 2014.