The final words spoken by a pilot of the missing Malaysia Airlines flight were not “All right, good night” but “Good night Malaysian three seven zero”, Malaysia’s civil aviation authority said.

Malaysian authorities have come under fire for their handling of investigations into Flight MH370.

They corrected the latest miscommunication in a statement released late yesterday.

“We would like to confirm that the last conversation in the transcript between the air traffic controller and the cockpit is at 0119 (Malaysian Time) and is “Good night Malaysian three seven zero,” the Department of Civil Aviation said in a statement.

“Good night Malaysian three seven zero” is a more formal, standard sign-off.

Malaysia’s ambassador to China had told Chinese passengers’ families, that the last words had been the more casual “All right, good night.”

False alarm on debris

Orange objects spotted by a plane searching for the missing Malaysia Airlines jet have turned out to be nothing more than fishing equipment, as prime minister Tony Abbott declared there’s no time limit on the search for MH370.

The Australian Maritime Safety Authority said the objects had been analysed and spokesman Jesse Platts said “they have nothing to do with the missing flight.”

An Australian P-3 Orion search plane spotted at least four orange objects in waters west of Perth on Sunday and were described by Orion pilot Russell Adams as the most promising lead in the search so far.

But despite yet another false alarm, Mr Abbott said the search will not be scaled down.

“I’m certainly not putting a time limit on it… We can keep searching for quite some time to come,” Abbott told reporters on Monday at RAAF Pearce, the Perth military base coordinating the operation.

“We owe it to the families, we owe it to everyone that travels by air, we owe it to the anxious governments of the countries who had people on that aircraft. We owe it to the wider world which has been transfixed by this mystery for three weeks now.”

The Australian naval vessel Ocean Shield conducted sea trials of hi-tech detection equipment on Monday before its 1850km journey to a tract of the southern Indian Ocean west of Perth.

The trials included a US Navy black box detector, an unmanned underwater vehicle and other acoustic detection equipment.

The Ocean Shield is expected to take up to four days to reach the huge, 319,000 square kilometre search zone, another navy ship, the frigate HMAS Toowoomba, at top speed reached the area by mid-morning on Monday after two days at sea.

It’s a race against time, given the box’s low-frequency acoustic beacon has a limited battery life. That has extended from an estimated 30 days to roughly 45 days, according to Captain Mark Matthews, a US Navy equipment specialist.

“These are rated to last 30 days, but that is a minimum. In my experience, they do last a little bit longer than that,” Capt Matthews said yesterday.

But the operation remained an extraordinarily difficult exercise, Mr Abbott said.

“We are searching a vast area of ocean and working with quite limited information,” he said after touring the Pearce base, where search planes from seven nations are being deployed, involving 550 personnel.

Defence Minister David Johnston said about 1000 sailors were looking for debris at sea – but the task was still onerous.

While each country involved was currently bearing its own costs, Australia was paying for running the co-ordination centre, which will have about 20 staff and be led by retired air chief marshall Angus Houston from Perth CBD headquarters.

Mr Abbott also said his Malaysian counterpart was not too hasty in announcing last week – before any debris had been recovered or confirmed as being from MH370 – that the plane was lost in the southern Indian Ocean and all on board were assumed dead.

“That’s the absolute overwhelming weight of evidence and I think that Prime Minister Najib Razak was perfectly entitled to come to that conclusion,” he said.

In China, home to 153 people on board the flight, a comment piece in the China Daily newspaper called for “rationality” among relatives – some of whom insist their loved ones could still be alive.

– with AAP