|(Flight MH370) Aussie acting PM Truss trips up on search info
Search crews have failed to relocate faint sounds heard deep in the southern Indian Ocean, possibly from the missing Malaysia Airlines Boeing 777's black boxes whose batteries are at the end of their life.
(Pictured, Australia's acting prime minister, Warren Truss).
Angus Houston, the retired Australian air chief marshal who is heading the search far off Australia's west coast, said sound locating equipment on board the Ocean Shield has not picked up any trace of the signals since they were first heard late Saturday and early Sunday. The detection of signals had reignited hopes, AP reports.
The locator beacons of the black boxes have a battery life of only about a month _ and today marks exactly one month since the plane vanished. Once the beacons blink off, locating the black boxes in such deep water would be an immensely difficult, if not impossible, task.
“There have been no further contacts with any transmission and we need to continue [searching] for several days right up to the point at which there's absolutely no doubt that the batteries will have expired,'' Houston said.
If, by that point, the US Navy listening equipment being towed behind the Ocean Shield has failed to pick up any signals, a sub on board the ship will be deployed to try and chart out any debris on the sea floor. If the sub maps out a debris field, the crew will replace its sonar system with a camera unit to photograph any wreckage.
Houston's comments contradicted an earlier statement from Australia's acting prime minister, Warren Truss, who said search crews would launch the Bluefin 21 autonomous sub today. A spokesman for Truss said the conflicting information was a misunderstanding, and Truss acknowledged the sub was not being used immediately.
The towed pinger locator detected late Saturday and early Sunday two distinct, long-lasting sounds underwater that are consistent with the pings from an aircraft's black boxes _ the flight data and cockpit voice recorders, Houston said.
Houtson said finding the sound again was critical to narrowing down the search area before the sub can be used.
Despite the excitement surrounding the Ocean Shield's sound detections, Houston warned that the search had previously been marred by false leads _ such as ships detecting their own signals.
The first sound picked up by the equipment on board the Ocean Shield lasted two hours and 20 minutes before it was lost, Houston said. The ship then turned around and picked up a signal again _ this time recording two distinct “pinger returns'' that lasted 13 minutes. That would be consistent with transmissions from both the flight data recorder and the cockpit voice recorder.
The black boxes normally emit a frequency of 37.5 kilohertz, and the signals picked up by the Ocean Shield were both 33.3 kilohertz, US Navy Capt. Mark Matthews said. But the manufacturer indicated the frequency of black boxes can drift in older equipment.