On March 30, the U.S. Navy loaded a Towed Pinger Locator and a submersible onto Australian defense vessel Ocean Shield. The Ocean Shield was joined this week by Royal Navy hydrographic survey ship HMS Echo, which is also equipped with "advanced environmental assessment capability" to scan the ocean surface for the MH370's black box transponder.
Friday's search marks "the first time that a sub-surface search will have been conducted in the search, in an attempt to detect the signal from the black box of MH370," the Australian Joint Agency Coordination Center noted Friday.
Commodore Peter Leavy, commander of Joint Task Force 658, explained how the 240-kilometer search area was determined.
"No hard evidence has been found to date so we have made the decision to search a sub-surface area on which the analysis has predicted MH370 is likely to have flown.
"While the preference for search operations is to use physical evidence and then drift modelling to determine a smaller sub-surface search area, the search track is considered to be the best estimate possible for an area likely to contain the crashed aircraft."
14 aircraft and 11 ships searched a total area of 217,000 square kilometers northwest of Perth. Although some objects were sighted by ships in the search area, none were associated with MH370.
Malaysia Airlines Flight 370 disappeared March 8 while flying from Kuala Lumpur to Beijing.
[Joint Agency Coordination Center]