US military saying that the vessel had other duties. Further funding and help from the US would have to be approved by the United States Congress. At the same time, external companies were suggested as possible retrievers of the black boxes. Indonesia continued to seek help from other countries, such as France and Japan. Indonesia's National Transportation Safety Committee head Setio Rahardjo maintained that Adam Air should be charged with the retrieval costs. It was originally confirmed that Indonesia would not pay for the salvage operation, and neither could they force Adam Air to do so. Nonetheless, Adam Air signed a contract with Phoenix International for the recovery operation. On 23 August, the Eas arrived in Sulawesi's Makassar port to begin salvage operations, which began with several days survey. The vessel was carrying a mini-submarine that could dive up to , and was equipped with sonar and deep sea cameras. A Phoenix International underwater robot scouring the sea off Majene for on Sulawesi finally retrieved the flight data recorder on 27 August and cockpit voice recorder on 28 August. The two devices were found at a depth of around and were apart. They had been moved from their original locations by powerful underwater currents. The black boxes were sent to Washington, D.C. for analysis. The final cost of the salvage operation to retrieve the black boxes was US$3 million, of which two million was contributed by the Indonesian government, with Adam Air paying the rest. Efforts continued with the hope of recovering various large pieces of wreckage from the seabed. Investigation President Susilo Bambang Yudhoyono ordered a full investigation to discover the cause of the aircraft's disappearance, including the cause of any accident it may have had, before the main debris field had even been found. The investigation also looked at the airworthiness of the plane and standard procedure on aircraft operations. A team from the United States with representatives from the National Transportation Safety Board, the Federal Aviation Administration, Boeing and General Electric were sent to Indonesia to assist the Indonesian National Committee for Transportation in the investigation. A wider investigation into Indonesia's transport system as a whole was planned. Eyewitnesses reported seeing a low-flying, unstable aircraft in the area from which the wreckage has been recovered but lost sight of it after hearing a loud bang. The chief of the Indonesian Aircraft Technicians Association, Wahyu Supriantono, said that