Navy spotters make mark

The giant US Navy P-8A Poseidon banked hard. Just outside a big observation window, towards the front of the plane, the ocean slipped past so close you could almost touch it.

Virtually skimming the waves at 90m above a remarkably calm ocean, about 2400km south-west of Perth, the sophisticated surveillance aircraft was on the hunt.

They were looking for any sign of the missing Malaysia Airlines flight. Anything at all.

From that distance they could have seen something as small as a dinner plate but what they were looking for was much bigger - two objects, one 24m long, spotted by satellites in the remote stretch of ocean and identified by Australian authorities as potential debris.

The target zone, about 320km south of the original search area in an incredibly remote stretch of the Indian Ocean, had been relayed to the crew around about the time the aircraft left Perth about 8.45am.

Media on the plane, including _The West Australian _ as the only Australian media outlet, were told the search area had been pinpointed because of information received that an object, described as "small to medium size", had possibly been identified floating on the surface.

On the three hour-flight out to the area, Lt-Cdr Mike Trumbull said that the information sounded promising.

As the aircraft began an exhaustive grid pattern search, the three pilots rotated through the cockpit as they flew the huge but agile aircraft at heights of between 90m and 460m. At a bank of screens towards the middle of the plane, five crew members monitored an array of radar images and controlled pictures from cameras attached to the aircraft's belly.

Two crew manned observation windows from which they constantly scanned the ocean.

At the rear of the aircraft, communication buoys had been loaded into chutes. One was "spat out" into the water to transmit data about the location and to enable calculations to be made about the rate of ocean drift.

There was strangely little noise aboard, apart from the drone of the engines, as the crew went about their tasks with minimum fuss and maximum concentration, communicating directly to each other through headsets. After several sweeps of an area of the zone that had been identified as having potential, a cargo vessel appeared to the aircraft's right, steaming out of low cloud.

This clearly was not the target. But before long an interesting hit on the radar had raised hopes, which fell again as it emerged that the cause of the blip on the bank of screens was a pod of dolphins, picked up by the equipment from a distance of 25km.

As the clock ticked towards the time at which the plane would reach its maximum search capability, another hit on the radar brought a series of low sweeps, intense concentration and anticipation.

But as 3pm ticked over and the crew reluctantly took the aircraft higher and turned for home, they revealed that what had held their interest on the screens this time had turned out to be a second pod of dolphins. After a remarkably smooth three-hour flight back to Perth Airport, the Poseidon landed about 6pm.

The crew searched an area of more than 10,619sqkm, travelling about 5310km and using radars that enabled them to pick up objects 32km on either side of the aircraft.

Despite having not solved the mystery of Malaysia Airlines MH370, Lt-Cdr Trumbull said he was satisfied with the mission.

"We cleared an area, I am confident there is nothing else out in that area," he said.