ON NEW year's day, 2007, a Boeing 737 airliner carrying 96 passengers and six crew members disappeared from the skies above Indonesia. Adam Air Flight 574 was en route from Java to Sulawesi when it vanished from air traffic control radar. No distress signals were received, and the aircraft had been successfully evaluated for airworthiness just a week before it disappeared. A sprawling search and rescue mission combed land and sea for several days without success. How could a 33-tonne airliner and 102 people simply vanish?

The mystery had echoes of the hugely popular TV show Lost, in which a Boeing 777 disappears into thin air. In the show, Oceanic Airlines Flight 815 is flying from Sydney to Los Angeles when it suffers multiple instrument failures. Its pilots attempt to divert the plane to Fiji, but 1000 miles off-course, it nose-dives, breaks into three pieces, and crashes on a mysterious island. Back in the real world, the fate of Flight 574 remained unknown.

The missing 737-400 was operated by short-haul carrier Adam Air, and was one of hundreds of planes that regularly hop between the Indonesian islands. Flight 574 left Surabaya, on the north coast of Java and around 150 miles west of Bali, at 12.55 local time. It was bound for Manado, a coastal resort on the northern tip of Sulawesi. Manado is just over 1000 miles north-east of Surabaya, across the Java Sea and Makassar Strait, and over Sulawesi's mountains and jungles and the equatorial line. On board for the two-hour flight were 91 adults, seven children and four infants.

Flight conditions were less than perfect. A storm was brewing over the Makassar Strait, and Flight 574 had received a weather warning before take-off. The Indonesian Bureau Of Meteorology And Geophysics was reporting that cloud cover was up to 30,000 feet, and wind speed was at 35 miles per hour. But the aircraft would be flying above the clouds at 35,000 feet, and there seemed little cause for concern.

However, by the time the plane reached the Makassar Strait the storm had worsened. Air traffic control at Makassar, on the southern tip of Sulawesi, warned the pilot to expect winds of up to 80 miles per hour coming from his right hand side. The pilot reported that the high winds were coming from his left. Had the plane changed course to avoid dangerous crosswinds? The confusion could not be clarified - there were no further radio transmissions, no calls for help, no distress signals.

At 13.53, 58 minutes into its journey, Flight 574 disappeared from air traffic control radars. Its last known position was 35,000 feet above the west coast of Sulawesi, between the towns of Mamuju and Pare-Pare. This remote and mountainous region was at the heart of the storm and thick with cloud. Search and rescue teams were dispatched, but it took them several hours to reach the area, and the terrain and weather made their hunt extremely difficult.

However, on the following morning, January 2, the Indonesian Air Force announced it had found the plane - and a handful of survivors - in the Sulawesi Mountains. It was reported that the plane was wrecked and there were many bodies, but that 12 survivors were sheltering in a nearby village. More than 100 rescuers were dispatched to the scene, but they found no survivors, no wreckage, and no trace whatsoever of Flight 574. Shockingly, the Air Force's claim had been completely false, being based upon bogus rumours passed from mountain villagers.

This led to distressing scenes at Manado's airport, where scores of relatives had gathered to await news of their loved ones. In a makeshift waiting room, people sat clutching photographs and holding each other. Some wept and wailed, and one woman collapsed on to the floor. There had been little reliable news, save for the release of the flight's passenger list that confirmed the names of the missing. How could their loved ones have disappeared without a trace?

Over the next few days, a sprawling search and rescue mission involving 3600 men, four aeroplanes, six helicopters, 12 ships and two mini-submarines combed land and sea. Through heavy rain and high winds, sonar-equipped planes and boats searched the broad Makassar Strait, while soldiers and rescue personnel cut through the thick jungles of the Sulawesi Mountains. Conflicting reports of sightings and transmitter signals dragged the search net wider and wider, covering an area of land and sea bigger than the British Isles. It was a vast and time-consuming task, and every hour that passed reduced the chances of any survivors being found alive.

THE missing aircraft was a 17-year-old former British Airways 737-400. Originally delivered to Dan-Air in 1989, the jet was owned by BA from 1992 to 1995. The 737 is the most popular passenger aircraft in the world - Boeing reckon there are around 1250 in the air at any one time. Several 737s have crashed since the model was introduced in 1968 - at least 60 according to the website airsafe.com - but, at 120ft long and with a 95ft wingspan, few have disappeared into thin air.

As the search continued, rescuers hiked towards high ground to seek vantage points, while relatives of passengers flew with search teams overhead. Shamans slaughtered a buffalo in a ceremony to seek the assistance of jungle spirits, and popular Indonesian psychic Mama Laurent directed the hunt towards Lake Tempe in southern Sulawesi. The Indonesian government announced it was spending a billion rupiah a day on the search effort, which converts to around £50,000 - a large sum of money, but hardly enough to mount a sophisticated rescue operation. But the country had limited resources and boundless problems.

Since the 2004 tsunami that killed more than 200,000 people captured the world's attention, Indonesia has endured an appalling catalogue of disasters. A series of earthquakes, volcanic eruptions, landslides, floods, plane crashes, ferry sinkings and bird flu outbreaks have claimed tens of thousands of lives. The last 12 months alone have seen the eruption of Mount Merapi on Java, major earthquakes and a tsunami hitting Java, Sulawesi and Sumatra, and catastrophic floods sweeping through Java and Sumatra. Just 24 hours before Flight 574 disappeared, a ferry carrying 628 passengers from Java to Borneo sank with the loss of almost 500 lives.

Indonesia is a country well used to dealing with tragedy, grieving for its lost, then moving on. And so, after five days of futile hunting for Flight 574, the search might well have been called off - had the missing not included an American family of three.

Among the names on the passenger list released by Adam Air were those of Scott Jackson and his daughters Lindsey and Stephanie. The girls, from Bend, Oregon, had been spending the holidays with their father, a businessman who lived and worked between Oregon, Indonesia and Brazil. The Jacksons were flying to Manado to go diving. Shortly before they left, the girls emailed their mother back in Bend to say Happy New Year. Then they boarded Flight 574 and were never seen again.

Eighteen-year-old Lindsey and 21-year-old Stephanie were both students at the University of Oregon. Lindsey was studying marine biology, and loved diving. Stephanie was a medical student who planned to help the sick in developing countries. The girls had two brothers: Greg had returned home a few days earlier; Brian, Lindsey's twin, had not made the trip.

Fifty-four-year-old Scott was the president of a rattan furniture manufacturer, and worked with timber companies around the world. He had recently divorced from the girls' mother, but often brought his children over to visit. Something of an adventurer, Scott's work had taken him on countless hazardous single-engine flights over inhospitable terrains. He had been a hostage of aggrieved employees in Brazil, and a passenger on a hi-jacked jet in Hong Kong. He had survived all of those dangers, yet now it seemed a holiday flight with his daughters might have killed him.

Indonesian vice-president Jusuf Kalla called the disappearance of Flight 574 an "international issue", and welcomed the assistance of a team from the US National Transportation Safety Board, in addition to help from the Canadian and Singaporean Air Forces. "It's impossible that it just disappeared," said Kalla. "Even if it takes a month, we have to keep searching."

In the TV show Lost, the missing aircraft is operated by Oceanic Airlines. Oceanic is a fictional company with an unfortunate history on movie and TV screens, having become something of a Hollywood inside joke. Since first appearing in the 1996 imperilled-airliner movie Executive Decision, the Oceanic name has popped up whenever writers require an ill-fated airline. Back in the real world, Adam Air was revealed as similarly disaster-prone.

Flight 574 was not the first Adam Air plane to disappear. Ten months earlier, an Adam Air 737 had disappeared en route from Jakarta to Makassar, only to reappear several hours later at a remote airstrip 300 miles off-course. The pilot blamed a loss of all communication and navigation systems, but Adam Air removed the plane before aviation officials could inspect it. The airline was severely criticised for breaking aviation regulations, and the investigation into the disappearance of Flight 574 raised further concerns about Adam Air's safety procedures. It was reported that the airline had skimped on maintenance costs and ordered pilots to fly in bad weather and in aircraft that were known not to be airworthy. It also transpired that pilots had made several specific complaints about the missing plane.

After every flight, pilots are required to record complaints regarding their aircraft, known as write-ups'. In the three months before Flight 574 disappeared, pilots had submitted 48 write-ups concerning the plane's vertical speed indicator and 30 write-ups concerning the left-right inertial reference system. These essential instruments tell the pilots at what speed the plane is ascending or descending, and in which direction it is turning. There had also been numerous write-ups about faulty cockpit lights, jamming flaps, and - perhaps crucially - a faulty weather radar. Could the pilots unknowingly have flown Flight 574 into the eye of the storm?

Meanwhile, the search effort had focused on an area of the Makassar Strait three miles west of Mamuju on Sulawesi's west coat. An Indonesian ship had located three large metal objects on the seabed, and US Navy vessel the Mary Sears travelled to the area to try to help identify them. However, the Indonesian Marine and Fishery Department suggested that the objects might be devices they had planted underwater to measure the sea current.

Then, on January 11, some 100 miles south of the concentrated search area, a fisherman found a piece of debris tangled in his net. He thought it to be a meaningless piece of plywood, and took it back to his stilted house in Pare-Pare and stashed it under his bed. Only later did he notice that the debris bore a serial number. He passed his catch to the local authorities - and was handed a reward of 50 million Rupiah (£2800). Airline technicians wiped tears from their eyes as they presented the fractured remains to the media. The fisherman had found the missing plane's right horizontal stabiliser - the first piece of wreckage from Flight 574.

Now it could be supposed that the aircraft had crashed into the ocean near Pare-Pare. Further discoveries seemed to confirm that theory. Pieces of aluminium, parts of an aircraft tyre, a food tray, a life jacket, and then a section of a passenger seat were all found. Then a search team pulled a five-foot long piece of one of the aircraft's wings from the sea. But there were no bodies.

Then, on January 15, came a gruesome discovery - a headrest with pieces of human hair and scalp stuck to it, floating several miles south of Pare-Pare. The remains were sent off for DNA testing. This latest find meant that debris from the downed plane was scattered over an area of 400 square miles.

Investigators and observers began to speculate over the manner of the plane's demise. Some believed it had broken up in mid-air after an on-board explosion or structural failure. This would explain the wide scattering of debris. Others suggested it had plunged into the ocean as a result of fin or rudder loss caused by crosswinds. A fall from 35,000 feet would have pulverised the plane and everyone in it.

On 21 January, the Mary Sears located Flight 574's black boxes - the flight data recorder and cockpit voice recorder - 40 miles off the west coast of Sulawesi. The boxes were almost a mile apart, and at depths of around 6000 feet. Salvage experts said that a specialist remotely operated underwater vehicle would be required to retrieve them - and Indonesia had no such equipment available. The black boxes, which could prove invaluable to crash investigators, had a limited battery life of around 30 days, after which they would cease to emit a locator signal and would be virtually impossible to find. Time was fast running out, and a dispute between the Indonesian government and Adam Air didn't help the salvage operation. The government initially questioned the need to recover the boxes, and then placed the responsibility for doing so with Adam Air. The airline said it was essential that the boxes were recovered, but said the government should pay for the operation.

Relatives of the missing, desperate to find answers and perhaps recover the bodies of their loved ones, expressed anger at the government and Adam Air. Adam Adhitya Suherman, the airline's founder, denied Adam Air's safety standards were to blame, but offered to compensate the families to the sum of 500 million rupiah (£28,000) each. He also agreed to build a memorial to the missing in Sulawesi. But groups representing the relatives weren't satisfied - they prepared to sue the airline for one trillion Rupiah (£50 million).

Adam Air's safety standards were again called into question in February 2007, when an Adam Air 737 crash-landed in Surabaya. The accident caused the fuselage of Flight 172 to crack along the wingspan. Then, in March, a Garuda Airlines 737 overshot the runway at Yogyakarta airport on Java and burst into flames, killing 21 people. The Indonesian authorities announced a shake-up of the country's aviation industry, and an investigation found that no local airline met all safety requirements. Adam Air was named as one of the worst offenders. The airline was given three months to improve its safety standards, or have its license revoked.

Flight 574's fuselage has not been located, and its black boxes - no longer transmitting - have not been recovered. Not a single body has been found. The Makassar Strait will continue to give up small pieces of wreckage - tiny clues in an enduring mystery - but it seems likely that, 6000 feet below the waves, Flight 574 and its 102 passengers and crew will remain forever lost.