An Indonesian jetliner that vanished with 102 people onboard did not issue distress signals or report any mechanical problems, a top aviation official said Thursday, adding to the mystery surrounding its disappearance. A Singaporean air force plane joined the massive land and sea search for the Boeing 737, which got off to a bad start when authorities wrongly stated Tuesday its wreckage had been found on Sulawesi Island along with a dozen survivors. Iksan Tatang, the director general of air transportation, said the Adam Air plane reported winds as high as 74 knots before losing contact with the ground on Monday midway through its flight from Indonesia's main island of Java to North Sulawesi's provincial capital, Manado. "The plane did not report any complaints about the navigation, the condition of the plane or other technical problems," he said, adding that two signals from its emergency beacon - which is activated on impact - were picked up by a plane in the vicinity and a satellite. Air Marshal Eddy Suyanto, the search and rescue mission coordinator, said the fact that the so-called Elba signal was dispatched from two separate locations would indicate an equipment malfunction. Transport Minister Hatta Radjasa said it was too soon to say what may have caused the crash. "I urge people not to speculate, we must wait until the National Commission for Transportation Safety has located the ill fated plane," he told reporters. A fleet of aircraft took to the skies, ships scoured the sea and soldiers battled rugged jungle terrain for the third day Thursday, searching a 72,500-square-kilometer area - roughly the size of Ireland or the US state of California. But by late afternoon they had seen no sign of the wreckage. Aviation experts said it was not unheard of for planes to go missing for days, though a lengthy search would hold up inquiries into the accident's cause. "In an area of low population density, particularly if it is in inhospitable terrain - such as jungle, or a deep ravine or covered by a canopy - it could sit for a long time without being found," said Laurence Benn, head of the Center for Civil Aviation in London. Relatives of the passengers - some camped out at the Adam Air counter at the Manado airport - were losing patience. More than 150 gathered at a crisis center outside the airport demanding information. "It's been three days, we just want to know what happened," said Selvi Kawengian, 43, whose younger brother was on the plane with his wife and 18-month-old son. Top Indonesian aviation, military and police officials - and the airline itself - earlier claimed the plane had been found in remote mountains. They said that 90 people on board had perished, but the remaining 12 survived. "Indonesia is a place full of miscommunication, contradictory information and confusion during an accident like this," said Nicholas Ionides, managing editor for Flight International Magazine in Asia. "There is gossip and rumor and you never know what the facts are."