A Chinese plane scouring the southern Indian Ocean for the missing Malaysian jet spotted two objects surrounded by smaller ones floating in the water, as a forecast for worsening weather conditions threatened to hamper search efforts in their 17th day.

The crew of a Chinese IL-76 aircraft reported sighting two “relatively big” floating objects to the Australian command center and to a Chinese icebreaker en route to the area, state- run Xinhua News Agency reported, citing one of its reporters on board. Many white smaller objects were scattered within a radius of several kilometers, it said.

The Chinese search planes scouring the area are heading back and the crew has asked the Australian authorities to send aircraft to further scan the area, Xinhua said. The crew reported coordinates of 95.1113 degrees east longitude and 42.5453 south latitude for the sightings.

After French satellite scans earlier showed floating debris near the search area, Australian Deputy Prime Minister Warren Truss tempered expectations when he said possible drifting objects were in a “completely different location” to where Chinese satellite imagery from March 18 detected a single large object. He also warned of the advance of an Indian Ocean storm toward seas in the search zone already known for high swells.

Cyclone Gillian

“Today we expect the weather to deteriorate and of course the forecasts ahead are not all that good,” Truss said in an Australian Broadcasting Corp. radio interview. The French sighting is about 850 kilometers (528 miles) north of investigators’ current focus “and is not in the area that’s been identified as the most likely place where the aircraft may have entered the sea.”

Severe Tropical Cyclone Gillian was moving south but wouldn’t have “any impact” on the area, Edward Boyles, a Perth-based forecaster with the Bureau of Meteorology, Australia’s government-funded weather agency, said in an interview.

He said rain was forecast for today and wouldn’t abate until tomorrow afternoon. “There will be moderate to fresh winds and lots of low clouds, which won’t be great conditions for the search,” Boyles said.

China’s aircraft were among the 10 flying off Australia’s west coast today in a zone covering 68,000 square kilometers (26,250 square miles), Truss said. Eight planes came up empty yesterday trying to locate a floating object spotted by a Chinese satellite.

Pinger-Locator

The U.S. Navy’s Seventh Fleet will move a black-box locator to the western Australian city of Perth so that if debris is found then a pinger-locator can be towed behind a ship to detect acoustic pulses.

Searchers are focused about 2,500 kilometers southwest of Perth in remote ocean waters in pursuit of the Boeing Co. 777-200ER flown by Malaysian Airline System Bhd. that vanished March 8 on a flight to Beijing from Kuala Lumpur with 239 people on board. Its intended path shouldn’t have gone anywhere near the southern Indian Ocean.

About two-thirds of the passengers were Chinese, spurring the government in Beijing to rush assets to help solve what has become the longest-running disappearance of an airliner in the modern era. The Chinese aircraft are Ilyushin Il-76 jets, a four-engine model that has seen service as a transport and military airborne command center.

Black Box

Three civilian planes -- two Bombardier Inc. Global business jets and an unspecified Airbus Group NV aircraft -- are part of the task force today as well, with 20 volunteer civilian observers on board. Australia, New Zealand, the U.S., China and Japan are operating military aircraft in the search.

Should the black box locator that is being moved to Perth be deployed, it will be towed behind a vessel traveling at speeds from one to five knots. It can detect the black box pinger down to a depth of about 20,000 feet, Cmdr. Chris Budde, U.S. Seventh Fleet Operations Officer, said in an e-mailed statement.

“This movement is simply a prudent effort to preposition equipment and trained personnel closer to the search area so that if debris is found we will be able to respond as quickly as possible since the battery life of the black box’s pinger is limited,” Budde said.

China Satellite

The black box is supposed to emit pings for 30 days after becoming immersed in water. While the black boxes are designed to withstand depths of 20,000 feet and may work in even deeper water, the range of the pings is a mile, according to manuals from Honeywell International Inc., the maker of the equipment.

China’s satellite imagery depicted a floating object 22.5 meters (74 feet) long. Malaysia’s transport ministry disclosed the existence of French data yesterday showing “potential objects in the vicinity” of the surveillance zone, without giving any coordinates.

The Chinese picture, taken March 18, is focused 90 degrees east and almost 45 degrees south, versus almost 91 degrees east and 44 degrees south for similar items on a March 16 satellite image, according to China’s State Administration of Science, Technology and Industry for National Defense. That put the object 120 kilometers southwest of the earlier sighting, the administration said.

Wooden Pallet

The dimensions appear similar to those of the larger of two objects seen previously, said to be 24 meters long. A Boeing 777-200 is 63 meters long, with a wingspan of 61 meters and a diameter of 6.2 meters.

Separately, the wooden pallet spotted from a civil search aircraft was among a number of small objects spread over 5 kilometers and could be of the kind used in planes, Mike Barton, an official with the Australian Maritime Safety Authority, Barton told reporters yesterday. The pallet appeared to show evidence of multicolored strapping belts, he said.

“The use of wooden pallets is quite common in the industry,” Barton said. “They’re usually packed into another container which is loaded in the belly of the aircraft.”

A New Zealand P3 Orion surveillance plane dispatched to the scene found only clumps of seaweed. Yesterday’s use of eight planes marked an increase from six previously, and included four long-range civil aircraft and a U.S. Navy P-8 Poseidon.

Sea Fog

There were “no sightings of significance” before nightfall, AMSA said. Sea fog impaired the air search for part of the day as a growing fleet of surface vessels converged on the area.

HMAS Success from the Royal Australian Navy has joined the hunt, while the Ocean Shield, equipped with a subsea remotely operated vehicle, is on its way to the zone. As is HMS Echo, a specialist ship from Britain’s Royal Navy that’s fitted with underwater listening gear and devices to survey the seabed.

The U.S. was asked by Malaysia to provide similar search technology, the Defense Department said in a statement.

An analysis of satellite pings shows that the Malaysian Airline System Bhd. 777 may have flown steadily across the ocean after diverting from its scheduled route to Beijing from Kuala Lumpur. That assessment gave the clearest idea yet on how investigators pinpointed a search zone.

Malaysian Prime Minister Najib Razak has said that the jet emitted pulse-like signals to a satellite about seven hours after last making voice contact, shifting the focus of the search to two arcs -- one extending north to Kazakhstan and the other into the southern Indian Ocean. The bulk of search efforts are focused on the south.

Northern Zone

In the northern zone, there have been no indications of the missing airplane on radar in China, India, Pakistan, Myanmar, Laos, Kyrgyzstan and Kazakhstan, Malaysia’s Acting Transport Minister Hishammuddin Hussein said.

Hishammuddin said a home-computer flight simulator belonging to the jet’s captain, Zaharie Ahmad Shah, has produced no clear leads for investigators.

The U.S. Federal Bureau of Investigation has received “digital media” from Malaysian authorities, including information from the simulator’s hard drive, and technicians are examining the data, according to a law enforcement official who asked not to be named because the probe is active. Michael Kortan, an FBI spokesman, declined to comment.

Some U.S. lawmakers renewed criticism of Malaysia’s government yesterday, saying they saw too little evidence of cooperation and too much emphasis on searching along a putative northern route taken by Flight 370.

“Across the board people are looking for more in the way of openness from the Malaysian government in terms of sharing the information they have in a timely manner,” Representative Patrick Meehan, a Pennsylvania Republican and a former federal prosecutor, said on CNN’s “State of the Union” program.

Through March 21, the U.S. spent $2.5 million on the hunt, according to a Defense Department spokesman, Army Colonel Steve Warren. The Pentagon has set aside $4 million, a sum that includes the expense for sending two destroyers, helicopters and patrol aircraft, Warren told reporters in Washington.