Ships and search planes are being sent to investigate a pulse signal that a Chinese patrol ship outfitted with a black-box detector picked up twice this weekend, says Australia's Angus Houston, who is leading the international search effort for the missing Malaysia Airlines jet. But he adds that it's too early to say whether the signal is a breakthrough in the search.
The signal's frequency is 37.5 kHz, according to Chinese media reports that we cited Saturday. While that frequency is used by emergency beacons such as airplanes' black boxes, it also reportedly has other uses, as well, which means the report is being treated with caution.
Malaysia Airline flight MH370 went missing with 239 people on board nearly 30 days ago — a crucial time frame for searchers, because jetliners' black-box equipment has enough battery power to send locator pings for about 30 days.
Chinese coast guard ship Haixun 01 picked up a signal Friday and again on Saturday afternoon, Houston said, with the second incident occurring less than 2 miles from the first. He says Australian and British ships are being sent to the area, with the Australian ship being delayed by the need to take a closer look at an "acoustic event" it had detected.
"This morning we were contacted by the Chinese authorities and advised that Haixun 01 had late yesterday afternoon redetected the signals for 90 seconds within just two kilometres of the original detection," Houston said, according to Australia's ABC news agency.
The signals were reported in an area that was recently made a new focus in the search after a review of satellite data, Houston said. Both signals were detected for less than two minutes, he said.
"The one the night before last lasted just a very short period of time. The one yesterday afternoon, I think it was 15:47 in the afternoon, was for 90 seconds. That's all we have got," he said. "It's not a continuous transmission. If you get close to the device, we should be receiving it for a longer period of time than just a fleeting encounter. But we have got a transmission, we must investigate it. That's the way we work."
The possible breakthrough had first been reported in Chinese media, leading to questions over whether China's ships were sharing information with Australian officials in a timely manner.
"China is sharing everything that is relevant to the search," Houston said. "Let me just say ... China has seven ships out there — that's by far the largest fleet of ships."
He added, "I think we should be focusing on the positives and not start saying, 'Are they doing this or doing that?' "
Asked by China's state-run media, Xinhua, to describe what it would potentially take to recover the black box in waters where the signal has been detected, Houston said it would be "challenging."
"The water in which Haixun 01 is working at the moment is 4,500 meters deep which is incredible, so any recovery operation is going to be very challenging and very demanding and will take a long period of time," Houston said. He added, "First of all, we have to establish the fact that there's something down there, we are a long way from making that conclusion."