This picture taken on March 8, 2014 shows military personnel scanning the sea aboard a Vietnamese Air Force aircraft taking part in a search mission ...
Arni Marlina, 36, a family member of a passenger onboard the missing Malaysia Airlines flight MH370, cries at a hotel in Putrajaya. (Reuters Photo)
A customs officer checks the travel documents and passports of passengers at Kuala Lumpur International Airport in Sepang. (Reuters)
This picture taken on March 8, 2014 shows an aerial view of an oil slick taken from a Vietnamese Air Force aircraft taking part in ...
Family members of those on board the missing Malaysia Airlines flight MH370 cry at a hotel in Putrajaya. (Reuters file photo)
A relative of a passenger onboard Malaysia Airlines flight MH370 cries at the Beijing Capital International Airport in Beijing. (AFP photo)
An information screen displays a message 'Let Us Pray For Flight MH370', regarding the missing Malaysia Airlines flight, at Kuala Lumpur International Airport. (Reuters)
A message 'Pray for MH370' is shown by mobile messaging app WeChat on a smartphone at Kuala Lumpur International Airport in Sepang. (AP Photo)
A man covers his face on his arrival at a hotel which is prepared for relatives or friends of passengers aboard a missing airplane, in ...
A woman in tears is helped by airport workers to a bus waiting for relatives of the missing Malaysian airliner at the international airport in ...
In an age when people assume that any bit of information is just a click away, the thought that a jetliner could simply disappear over the ocean for more than two days is staggering. But Malaysia Airlines Flight MH370 is hardly the first reminder of how big the seas are, and of how agonizing it can be to try to find something lost in them.
It took two years to find the main wreckage of an Air France jet that plunged into the Atlantic Ocean in 2009.
Closer to the area between Malaysia and Vietnam where Saturday's flight vanished, it took a week for debris from an Indonesian jet to be spotted in 2007. Today, the mostly intact fuselage still sits on the bottom of the ocean.
Read: Massive air and sea search on for missing Malaysian jet, stolen passports probed
"The world is a big place," said Michael Smart, professor of aerospace engineering at the University of Queensland in Australia. "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?"
Amid the confusion, officials involved in the search say the Malaysian jet may have made a U-turn, adding one more level of uncertainty to the effort to find it. They even suggest that the plane could be hundreds of kilometers from where it was last detected.
A US Navy SH-60R Seahawk helicopter takes off from the destroyer USS Pinckney in the Gulf of Thailand, to assist in the search for missing Malaysian Airlines flight MH370. (Reuters)
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.
"I'm absolutely confident that we will find this airplane," Capt John M. Cox, who spent 25 years flying for US Airways and is now CEO of Safety Operating Systems, said Monday.
The modern pace of communications, where GPS features in our cars and smartphones tell us our location at any given moment, has set unreal expectations. "This is not the first time we have had to wait a few days to find the wreckage."
Based on what he's heard, 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."
Malaysian civil aviation chief Azharuddin Abdul Rahman, whose agency is leading a multinational effort to find the Boeing 777, said more than 1,000 people and at least 34 planes and 40 ships were searching a radius of 100 nautical miles around the last known location of Flight MH370. No signal has been detected since early Saturday morning, when the plane was at its cruising altitude and showed no sign of trouble.