Marshal Angus Houston , who led the search operation , said the plane detects a signal near the Royal Australian Navy ship Ocean Shield on Thursday ( 10/3 ) , yesterday .
Houston said , further analysis is required , but the signal may come from a man-made sources .
Has narrowed the search area of 75 thousand square kilometers to about 58 thousand square kilometers . Searches carried out after four signal detected in an area of less than 40 kilometers away from the U.S. Navy 's search tool installed by Ocean Shield . The fifth signal detected by the plane that captures the transmission of a listening device mounted near the ship Ocean Shield .
Center of the search area is located approximately 2,280 kilometers north-west of Perth . The black box flight recorders will probably give an answer about what happened swampland plane , carrying 227 passengers and 12 crew when it disappeared on March 8, on a flight from Kuala Lumpur to Beijing .
The battery of the black box may be dead after 30 days , so the effort to find it at the bottom of the ocean becomes more difficult .
Search efforts are now focused on two areas - aircraft and ships in the area around 2,240 kilometers north-west of Perth . Included in the smaller area of about 600 kilometers closer to the West Australian .
The experts argue , this operation is a very difficult task .
" Working near the bottom of the sea is very difficult because it is unfamiliar territory : no one had ever been there before , " said University of NSW marine experts , Erik van Sebille .
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Air Marshal Houston agrees and warns , because the sea is deep, so the search for the missing plane was going to be very difficult .
Conditions of silt on the sea floor also complicate efforts to capture a black box .
" Silt is material that tends to be very deep and something that falls there will be swallowed up by the silt on the sea floor , " he said recently .