An unmanned submarine on its seventh dive for the missing Flight MH370 may complete its mission in the southern Indian Ocean within a week, said the Australian agency conducting the search.

The Bluefin-21 is combing an area within a 10-kilometer (6- mile) radius of a black-box signal detected on April 8, according to the Joint Agency Coordination Centre in Perth. The search is at a “critical juncture,” Malaysia’s Transport Minister Hishammuddin Hussein said in Kuala Lumpur.

“We’re satisfied with progress so far, although there has been some planning adjustments,” the JACC said in an e-mailed response to questions today. “We should complete the search of the focused underwater area in five to seven days.”

At 43 days, the hunt for the Malaysian Airline System Bhd. plane that disappeared March 8 with 239 people on board, is the longest for a missing passenger jet in modern aviation history. As many as 11 military aircraft and 12 ships will comb the waters off Western Australia for debris today, while the Australian Maritime Safety Authority has planned a visual search of 50,200 square kilometers, it said earlier on its website.

The submarine failed to find “contacts of interest” during its sixth dive overnight and data from the mission is being reviewed, according to the JACC. Analysis of an oil slick found last weekend in the search area showed the substance didn’t come from an aircraft engine or hydraulic fluid, it said.

Black Boxes

The Bluefin-21’s side-scan sonar is pivotal as the batteries in Flight 370’s black boxes have probably expired. Four audio pulses from the crash-proof recorders were detected from April 5 to April 8.

Reports that the submarine could take as long as two months to scan the entire area are incorrect as detailed acoustic analysis has allowed the search to be narrowed, the Australian newspaper said today, citing JACC head Angus Houston. The former air chief marshal declined to specify how long it would take, according to the paper.

“I have to stress that this is not to stop operations but to also consider other approaches which may include widening the scope of the search and utilising other assets,” Hishammuddin said at a press briefing today. “All efforts will be intensified. Whatever the outcome of the next few days, we need to re-group and re-consider the operations.”

Route Deviation

The missing Boeing Co. 777 strayed from its intended flight path to Beijing from Kuala Lumpur, turning “leftward” in Vietnamese airspace before vanishing from radar screens, CNN said on its website yesterday, citing an unnamed Malaysian aviation source. It climbed to 38,000 feet (11,582 meters) and flew at that altitude for about 20 minutes over the Malaysian Peninsula before descending, it reported.

The aircraft was equipped with four emergency-locator transmitters designed to send signals to a satellite when triggered by a crash or by contact with water, CNN said.

The Bluefin-21, which bounces sound waves off the ocean floor to create images of terrain, is designed to be deployed for 24 hours at a time. Its first foray was cut short when a built-in safety feature forced a return to the surface after it dived deeper than its operating limit of 4,500 meters.

A second attempt was interrupted by a battery malfunction, according to Jim Gibson, the general manager of Phoenix International Holdings Inc., the contractor performing the search. The software has been adjusted to allow the submarine to go deeper, the JACC said.

With assistance from David Fickling in Sydney and Chong Pooi Koon and Elffie Chew in Kuala Lumpur. To contact the reporters on this story: Edward Johnson in Sydney at; Alan Levin in Washington at; Nichola Saminather in Sydney at To contact the editors responsible for this story: Anand Krishnamoorthy at 

Photo Credit: The Bluefin-21 Autonomous Underwater Vehicle is craned over the side of the Australian Defence Vessel Ocean Shield in the southern Indian Ocean. Australian Defence Force/Handout via Reuters