With no other data available indicating

With no other data available indicating where the plane went down, spotting wreckage is key to narrowing down the search area and ultimately finding the plane's flight data recorders, which will provide a wealth of information about the condition the plane was flying under and possibly the communications or sounds in the cockpit.
The data recorders emit a "ping" that can be detected by special equipment towed by a ship in the immediate vicinity. But the battery-powered recorders stop transmitting the "pings" about 30 days after a crash. Locating the data recorders and wreckage after that is possible, but it becomes an even more daunting task.
Houston said that only once wreckage from the plane was found "we will then be able to narrowly focus the search area so that we can start to exploit the underwater technology devices that will hopefully lead to where the aircraft is on the bottom of the ocean."
Malaysia has been criticized by the relatives of some Chinese passengers on board, who accuse them of not giving them enough information or even lying about what it knows about the final movements of the plane. Some are staying in hotels in Beijing and Kuala Lumpur, courtesy of Malaysia Airlines.
On Wednesday, authorities organized a closed-door briefing in Malaysia for the families with officials and experts involved in the hunt.
It was relayed by video conferencing technologies to the relatives in Beijing. Several relatives interviewed after session said they were still not satisfied.
"The fact is they didn't give us any convincing information," said Steve Wang, a representative of some of the Chinese families in Beijing. "They said themselves that there are many different possibilities, but they are judging on the basis of just one of them."
Malaysian officials have on occasion given conflicting accounts and contradictory information over the last three weeks. They maintain they are doing their best in what it is an unprecedented situation, and stress they want the same thing as the families, namely to locate the plane as quickly as possible.