(Adds new quotes on underwater object found, flight simulation) By Ahmad Pathoni MAKASSAR, Indonesia, Jan 8 (Reuters) - An Indonesian navy ship detected a large metal object on the ocean floor on Monday, but officials were not certain it was the wreckage of an airliner that disappeared a week ago around Sulawesi island. The ship's sonar picked up a signal with quite significant noise 1,050 metres (1,148 yards) under the sea north of Mamuju, a seaside town in West Sulawesi province, said Tony Syaiful, spokesman for the navy's Eastern Fleet. "It is clearly metal, but we cannot confirm what it is. Four more navy ships will be sent to coordinate. We may lower a mini-submarine for underwater observation," he said. The Adam Air went missing in bad weather on New Year's Day after the pilot reported crosswinds and asked for safe coordinates from the airport in Makassar, Sulawesi's largest city. But he did not issue a mayday call or report any malfunctions on the plane, which took off from Java island for the North Sulawesi capital, Manado. The USNS Mary Sears, a U.S. ship with sonar capability and the ability to detect metal underwater, will arrive on Tuesday to join the search, which already includes at least four ships, two Indonesian air force planes, two helicopters, and thousands of troops and police on the ground. "We are waiting for the U.S. ship which could help us with its high technology," Syaiful added. Indonesian officials will be cautious in announcing any discovery after erroneously saying the plane had been spotted in Sulawesi's mountains on Tuesday when accounts from a local village were relayed to the highest level without checks. PILOT'S ANGUISHED SEARCH Pilot Lucky Setiandika, whose wife of two months was one of the 102 people on board the plane, has been on several of the search missions over the mountains and jungles of Sulawesi. "Sortie after sortie, we return empty-handed. You can imagine how I feel," first-lieutenant Setiandika, 25, said on Monday at a military airbase in Makassar, the capital of South Sulawesi province where the search effort is being coordinated. "I hope she's still alive, eating whatever she can in the forest. I want to take her home alive." A military spokesman said on Monday two more Indonesian Air Force helicopters will take part in the search for the 17-year-old Boeing 737-400. The search was focused on the Bone Strait between the two southern arms of Sulawesi island and the onshore areas of western Sulawesi, Captain Mulyadi said in Makassar. In addition to the U.S. ship and an American military plane, Singapore has sent an Air Force Fokker-50 search plane. "The United States has extended their help. The foreign ministry will not hesitate in giving permission and clearance for their efforts in helping us," Indonesian Foreign Minister Hassan Wirajuda told reporters in Jakarta on Monday. The plane disappeared less than three days after a ferry with more than 600 aboard capsized and sank off Java. Fourteen survivors of the ferry have been rescued after drifting on a life raft for nine days, a top search and rescue official said on Monday. At least 248 survivors have been found, some clinging to wreckage or floating in life vests, and others on life rafts. The latest survivors were found about 480 km (300 miles) from the accident site early on Sunday morning, according to Karnoyudho, who is head of the national search and rescue agency. Indonesian President Susilo Bambang Yudhoyono has called for an investigation into what went wrong in both cases as well as a general probe into the state of Indonesia's transport system. The network serves 220 million people in an archipelago of 17,000 islands. (With additional reporting by Muara Makarim, Achmad Sukarsono and Muhammad Azhari in Jakarta)
