The Australian Transport Safety Board (ATSB) has issued this update on the on-going search for missing Malaysia Airlines flight MH 370:

At the request of the Malaysian Government, Australia is leading the search for missing Malaysia Airlines Flight MH 370. All the available data indicates the aircraft entered the sea close to a long but narrow arc of the southern Indian Ocean.

The complexities surrounding the search cannot be understated. It involves vast areas of the Indian Ocean with only limited known data and aircraft flight information. While it is impossible to determine with certainty where the aircraft may have entered the water, all the available data and analysis indicates a highly probable search area close to a long but narrow arc of the southern Indian Ocean.

MH 370 Operational Search Update September 24, 2014

This operational report has been developed to provide regular updates on the progress of the search effort for MH 370. Our work will continue to be thorough and methodical, so sometimes weekly progress may seem slow. Please be assured that work is continuing and is aimed at finding MH 370 as quickly as possible.

Bathymetric survey

The bathymetric survey provides a map of the ocean floor to ensure the safe and effective operation of equipment during the underwater search.

Over 106,000 square kilometers of the wide search area have been surveyed (see map below).

The priorities for the search will continue to be reviewed and will change over time.

Ship movements

After resupply in Fremantle, Fugro Equator commenced passage back to the search area on September 19 and arrived on September 24 to recommence survey work in the search area in preparation for the underwater search.

On September 20, the Chinese survey vessel Zhu Kezhen completed her MH 370 search mission and commenced return passage to China.

The Chinese support vessel Haixun 01 continued to be stationed at the Port of Fremantle for repairs.

Weather

A series of cold fronts will move through to the south of the area over the next four days. A significant front will approach from the west on Friday. Sea conditions between sea states 2 and 7 are expected over the next three to four days.

Underwater search

Vessels involved in the search are being jointly funded by Malaysia and Australia. Fugro Discovery and Fugro Equator (which is currently being used to survey the search area) are Fugro Survey Pty Ltd vessels, and the GO Phoenix has equipment and experts provided by Phoenix International (Phoenix).

Ship movements

Mobilization of search assets is already under way. GO Phoenix received fit-out work in Jakarta in preparation for the sea and weather conditions it is likely to encounter in the search area. GO Phoenix departed Jakarta on September 23 for the calibration area and is expected to arrive at the allocated underwater search area on October 1. GO Phoenix will search there for around 20 days before sailing to Fremantle to be resupplied.

Fugro Discovery has completed fit-out work in Durban, South Africa and commenced passage to Australia. The vessel is expected to arrive in Fremantle on October 2, whereupon search equipment and a mission crew are expected to be mobilized.

Fugro Equator, the vessel currently being used to survey the search area, is expected to be mobilized as a search vessel when its bathymetric work is complete around the end of October.

Planning

The ATSB, in consultation with the contracted search experts, is in the process of finalizing the initial plan for the underwater search, to be followed and referred to by all parties involved in the underwater search. The comprehensive plan for the underwater search will include a sequence of priority areas. The first area to be searched has already been surveyed to ensure an accurate understanding of the sea floor topography.

Search priorities

From early in the search, analysis has consistently indicated a very high probability of finding the aircraft along a defined arc in the southern Indian Ocean (where the aircraft last communicated with a ground station through a satellite). This is where the aircraft is assessed to have run out of fuel.

Since then, complex, ground-breaking technical analysis of limited communications data and aircraft flight information has been developed and refined. This work has concentrated on determining the point on the seventh arc that the aircraft was most likely to have reached. This will enable a prioritized search effort in areas along the seventh arc.

Map: The Seventh Arc in the southern Indian Ocean.

Recent refinement to the analysis has given greater certainty about when the aircraft turned south into the Indian Ocean and has produced a better understanding of the parameters within which the satellite ground station was operating during the last flight of MH 370.

Based on these refinements, the Search Strategy Working Group is finalizing its latest assessment of the highest priority areas for the search, which will most likely extend south of the previous ‘orange’ priority area.

Top Image: ATSB. Three-dimensional model of the sea floor terrain in the search area.