Australian authorities will deploy an underwater vehicle on Monday evening to continue the search for the missing Malaysia Airlines plane, as it is now believed unlikely there will be any further sonar detections of the black boxes.
The search for the missing plane, which is believed to have crashed in the Indian Ocean, claiming the lives of all 239 passengers on board, will enter a new phase now on the 38th day since the plane went missing, involving an underwater search vessel known as “Blue Fin 21” that will be deployed from the Australian defence vessel Ocean Shield.
The vehicle is sent out on 24-hour search cycles, and will spend four hours on the Ocean Shield after each search, having its batteries charged and allowing the data to be downloaded and analysed. Private contractors for the US navy from Phoenix International will analyse the data onboard the Ocean Shield.
The head of Australia’s joint co-ordination centre, Angus Houston, said on Monday: “We haven’t had a single detection in six days so it’s time to go underwater … The deployment of the underwater autonomous vehicle allows us to take a step forward.”
A series of pings detected by the Ocean Shield have allowed authorities to narrow down the search zone to a much smaller area.
The vehicle will undertake a “scanning search” that will attempt to cover as much ground as possible and allow search officials to produce a high-resolution map of the sea floor.
US navy captain Mark Matthews, who is overseeing the use of the underwater vehicle, said Blue Fin 21 was chosen for the search because of its quick deployment. “It was chosen for its speed of deployment, and principally the mission right now is to localise. It’s got a tactical capability to do those debris fields but it’s certainly not the tool I would use to do a very, very broad area sonar scan,” he said.
The vehicle uses a sonar pulse to determine whether there are artificial or man-made objects that may be resting on the ocean floor, which is believed to be approximately 4,500m deep. “What this does is active sonar. It sends out a ping, sound energy, and it listens for the return. The time between the ping and receive tells it how far away that object is and the intensity of the sound tells it how dense or hard or strong that contact is,” he said.
Matthews added that the search using the underwater vehicle was likely to unfold slowly: “If we find it on day one I would be shocked … People need to realise these searches typically unfold over months and years, certainly not hours and days.”
Houston also said an oil slick had been detected around 5,500m from the last pings that were detected by the Ocean Shield. A sample had been collected but it would take “several days” before results came back.
Up to 11 military craft, one civil aircraft and 15 ships will be involved in the search on Monday.