Two ships equipped with deep sea stingray-shaped sound locaters have been sent to sweep the area where the flight MH370 is estimated to have ended in the last desperate attempt to locate the black boxes before their batteries are drained.
Although no pointers have been found narrowing down the area of the possible crash in the southern Indian Ocean where international teams have been searching for signs of wreckage of the missing plane in the past weeks, officials said that with the one-month life time of the black box batteries nearing the end, there is more to gain than to lose.
"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," Commander Peter Leahy, who is leading the military forces involved in the search, said.
Two ships with sophisticated equipment that can intercept the pings transmitted by the Flight Data Recorders even if they were at the bottom of the ocean are currently sailing along the 240km route the investigators believe may be close to the presumed crash-site.
"They might be lucky and they might start smack bang right over the top of it," said Geoff Dell, discipline leader of accident investigation at Central Queensland University in Australia. "But my guess is that's not going to be the case and they're in for a lengthy search."
Angus Houston, head of Australia’s new joint agency overseeing the search for the missing Malaysia Airlines flight MH370, said: "The locater beacon will last about a month before it ceases its transmissions - so we're now getting pretty close to the time when it might expire."
The Australian navy ship Ocean Shield towed a pinger locator from the US Navy and the British navy's HMS Echo, equipped with similar gear, looked for the black boxes in an area investigators' settled on after analysing hourly satellite pings the aircraft gave off after it disappeared.
However, the search progress is rather slow as the locators, 70cm-long cylindrical microphones, have to be towed behind the ship at a speed of only six miles per hour.
The locators are dragged through the water attached to a 6km-long cable steered by a yellow triangular carrier with a shark fin on top. The device, resembling a stringray, has a wingspan of about one metre.
The current search area is 217,000 square kilometres in size and lies within a larger zone constantly criss-crossed by 14 planes and nine ships in the hunt for any sign of wreckage.
The search zone is about 1,100 miles (1,700km) north-west of the Australian west coast city of Perth.
Beijing-bound Flight MH370 got lost on 8 March about an hour after take-off from Kuala Lumpur. 26 countries have already joint the search efforts so far without any success.