Flight 370: Satellite firm picked south on day two

A woman writes a message on a board dedicated to the passengers aboard the missing Malaysia Airlines Flight MH370. Photo / AP

Families want to know why it took nine days to move search to sea off Australia

Flight MH370 had been missing for just two days when engineers from a satellite company concluded the plane probably crashed in the southern Indian Ocean.

Yet it was almost another week before the focus of the multinational hunt shifted to rough seas off south-western Australia - and nine days before searching got under way in earnest.

Last night families of the 239 people on-board demanded to know why there had been such a long delay, which experts said made the search even harder because winds and ocean currents would have spread debris far from an original crash site.

The revelation adds fuel to criticism of the Malaysian-led investigation, which has often appeared chaotic and marred by confusing and sometimes contradictory statements.

Vital "pings" that continued to be sent to a satellite were first accessed by technical experts the day after the Malaysia Airlines plane disappeared from civilian radar off the country's northeast coast on Saturday, March 8.

By Monday the team at the satellite's owners, Inmarsat, were "fairly certain" the Boeing 777 had most likely flown for around another seven hours.

The British firm sent its analysis to a Swiss aviation IT provider the next day, which is said to have then informed Malaysian officials the day after that - on Wednesday, March 12.

At that point the international search effort was focused on the South China Sea and Straits of Malacca.

But it wasn't until last Saturday, when Malaysian Prime Minister Najib Razak declared the plane had been diverted deliberately, that focus shifted sharply to two new enormous search areas stretching thousands of kilometres into the Northern and Southern Hemispheres.

Although investigators in Kuala Lumpur continue to stress the importance of both corridors, American and British intelligence officials are believed to have dismissed the northern option because the plane wasn't picked up by radar over several countries with strong air defences.

The focus on remote waters more than 2000km southwest of Perth has been ramping up since last Sunday, after Malaysian investigators asked Australia to co-ordinate the hunt.

The Inmarsat satellite continued to capture a series of hourly "handshakes" from the ill-fated Beijing-bound Boeing 777 after its communications systems shut down shortly after take-off from Kuala Lumpur.

"Our engineers looked at the time between the handshakes, and they realised that the object wasn't stationary under a satellite but moving away from it," Inmarsat senior vice-president Chris McLaughlin told the Washington Post.

According to the Wall Street Journal, the company became concerned the data was not being acted upon and approached UK security authorities for assistance. Malaysia Airlines was also said to have told the Swiss firm to use the UK's Air Accidents Investigations Branch as a "primary conduit".

It remains unclear why the Malaysian investigators took several days to act on the information, and change the focus of the search.

The Journal said its government was concerned about corroborating the data, and dealing with internal disagreements on the public release of information. "We don't want to upset anybody with round after round of confusing information," one official told the paper.

The Inmarsat "pings" suggest the plane flew steadily at cruising speed of around 800km/h across the Indian Ocean. That satellite orbits more than 35,000km above the Earth and the WorldView-2 satellite that photographed possible wreckage circles at just 700km. Owners DigitalGlobe say the high-resolution satellite can capture images of objects as small as a basketball.