BANDA ACEH, Indonesia — Most every day, small bands of men, women and sometimes children congregate on a surviving piece of roadway or gather along crescents of coastal sand to flag down the U.S. Navy helicopters.

The tsunami survivors signal with white and yellow pieces of cloth, or whatever else they have on hand in a determined — at times, desperate — bid to make the helicopters land.

On Wednesday, Navy Lt. Cmdr. Mark Leavitt saw more than half a dozen of these groups in an afternoon flight along Sumatra's tsunami-wracked northwest coast. He had already made a scheduled delivery, and his Sikorsky helicopter was almost empty of food. Without much to offer, and little time to spare, he passed by all but one of the groups.

"The flag is supposed to signal distress," Leavitt said. "But we don't know if they've got someone hurt, or are just hungry. And if we stopped to check on every one of these groups, we would never get our [scheduled] deliveries done."

The ubiquitous presence of the flag wavers, nearly a month into one of history's biggest helicopter food lifts, is evidence of the still-tenuous existence for some survivors of the Dec. 26 tsunami.

Though tens of thousands have been moved into camps along roadways or areas accessible by sea, thousands more are still dependent on the helicopter lifeline forged by the U.S., Australia, France, Great Britain and other nations.

The helicopter is a far less efficient — and more costly — method of transport than trucks or boats. Some of the smaller aircraft may cost as much as $2,000 an hour to operate yet carry less than 2,500 pounds in a village load.

But land and sea routes have been slow to open up to the northwest Sumatra villages. So the helicopter airlift has actually expanded during the past weeks.

And its success has helped the Indonesian officials postpone tough decisions about whether villagers will be allowed to stay in their home territory, as most appear to desire, or join the other displaced people in more accessible locations.

A senior Australian military officer, quoted in The Australian newspaper yesterday, questioned how long such pricey airlifts would remain viable.

"This is an issue for the Indonesians to assess," Lt. Col. Peter Steel, who oversees Australian helicopter operations, told the newspaper. "Do they relocate these people, because we can't keep flying helicopters down the west coast forever?"

Thousands of pounds daily

The U.S. airlift fleet numbers more than 30 helicopters. It sometimes moves nearly 300,000 pounds in a day, compared to less than 70,000 pounds a day in the initial flights in early January.

Navy officials here say they are not sure of the precise numbers of people fed by the air drops. But the total amount of food and supplies moved by the U.S. fleet has topped 3 million pounds delivered on more than 1,030 flights. And the airlift, which makes scheduled deliveries in some 15 locations, is likely to continue for weeks into the future.

"The mission we got was to feed the people of Indonesia. [We] don't attach a dollar amount to it," said Lt. Cmdr. John Bernard, an officer with the USS Abraham Lincoln.

The Everett-based Abraham Lincoln, an aircraft carrier with some 5,000 crew members, was one of the first U.S. military vessels to arrive off Indonesia, and has played a central role in the huge airlift. It contributes 16 helicopters, as well as dozens of crew who fly ashore each day to a soccer field near the Banda Aceh airport.

There, the crew form human chains that pass bags of rice, noodle packets, jugs of water and occasionally boxes of humanitarian rations to the helicopters that touch down on the turf. During breaks, they munch on Pringles, Pop Tarts and chilled soda flown in from the well-stocked galleys of the Abraham Lincoln. In a slack moment, they amuse themselves betting on the outcome of a face-off between a water buffalo and dogs that meander near the helicopter landing pad.

This shore duty is immensely popular among the crew, who covet the job as a welcome break from the tedium of the sea and a chance to get involved with a historic relief effort.

"This is something I wanted to do since the moment I heard about it," said Information Technician 2nd Class Richard Lane of Roseburg, Ore. "Three-quarters of the crew volunteered to do this, but some of the folks are just too important to let go, the guys that make the water, and keep the lights on."

Helicopter pilots and their crew often work 10- to 12-hour days, navigating through remote terrain with heavy payloads to reach makeshift landing pads.

"I have flown more hours in two weeks than I normally fly in two months. We've been very excited to be a part of this, but we also have to be careful to get enough rest," said Lt. John Burroughs, a Sikorsky pilot.

"We're definitely pushing the envelope to help the Indonesians."

The flying gives the pilots a spectacular view of the changes wrought by the tsunami.

In some areas, where the river valleys pierce the mountains, the sea rushed in more than a mile to claim the land. Beaches have eroded to slivers of sand, and river mouths have become boggy deltas that prevent inland passage.

The tsunami also swamped thousands of acres of farm land that once grew rice, fruit and vegetables. Though clusters of palm trees managed to survive the waves, much of the vegetation looks as if it had been sprayed with the herbicide Agent Orange.

"Surreal" landscape

On the way south out of Banda Aceh, the pilots time and time again pass over the flattened town of Lokna, where only a mosque still stands and thousands perished from the waves.

"Every time we fly, we will be discussing how this is so surreal. It is something I have never seen anything like, and something I hope to never see anything like again," Burroughs said.

Yesterday, the helicopter delivered a load of a food to a hillside hamlet that rises above a drab brown swamp. Dozens of people there live under blue tarps strung among the trees; farming and fishing families whose lives are now keyed to the daily heli-

copter drops.

As the helicopter touched down on a piece of roadway bordering the swamp, the villagers rushed down from the hill to get bags of rice and boxes of humanitarian rations specially formulated for Muslim countries with dishes such as lentil stews. When the helicopter took off a few minutes later, the villagers offered smiles and handshakes.

Some landings can be more chaotic. On roughly 20 percent of their deliveries, Leavitt and Burroughs say they are rushed by hungry people, many still subsisting on one starchy meal a day of rice or noodles.

"A lot of the people are still charging the helicopter," Leavitt said. "They don't get violent with us, but try to forcibly get into the helicopter."

To try to ease the burden on the helicopters, the U.S. Marines are now deploying hovercraft to help deliver loads along the coast. Indonesians also are trying to increase the range of maritime deliveries. One option might be to use more village fishing boats to ferry supplies ashore.

Skilled local navigators can take some of these narrow wood boats out through breakers that would swamp larger vessels, but many of these boats have been destroyed and those that still exist often lack fuel.

So the airlift is likely to continue for weeks.

"We'll be here until the Indonesians say they don't need us anymore," said Bernard, the Lincoln officer.

Hal Bernton: 206-464-2581 or hbernton@seattletimes.com