A flight data recorder retrieved Tuesday by Indonesian authorities is the best chance of identifying the circumstances that led to a Sriwijaya Air Boeing 737 plunging into the sea shortly after take-off on Saturday. The tragedy claimed 62 lives when the 26-year-old Boeing 737-500 crashed less than five minutes after taking off Jakarta’s Soekarno-Hatta International Airport. Several media outlets confirmed Tuesday that one of the black boxes had been found and had been shipped back to Jakarta. The Australian reported National Transportation Safety Committee deputy chief Haryo Satmiko confirmed it was the flight data recorder and that investigators were still searching for the cockpit voice recorder. Officials located the black boxes on Sunday but ran into trouble retrieving them because of wreckage strewn across the seafloor. The search was also hampered because underwater beacons designed to help searchers locate the devices had become detached, officials said. The head of the National Transport Safety Committee, Soerjanto Tjahono, said it would take two to five days to read the flight data recorder's data. “We are expecting that through this investigation we can unfold the mystery of this accident,’’ he told CNN. Officials believe the plane was still intact when it hit the sea on January 9 because of the spread of the wreckage and the fact the aircraft was transmitting information as it plummeted. They say this rules out a mid-air explosion. Flight SJ182 was not on its assigned heading but the pilots did not respond to queries from air traffic control about the change. Why this was so will be among the questions investigators will be hoping information on the black boxes will answer. The aging Sriwijaya plane was about 11 nautical miles north of Jakarta’s Soekarno-Hatta  International Airport on a flight between Jakarta and Pontianak in Borneo when contact was lost. It was under the control of experienced pilots and officials revealed Tuesday it had been grounded during the COVID-19 pandemic and passed an inspection to return it to service on December 14. It made its first flight about five days after the inspection without passengers and returned to service shortly afterward. Searchers have retrieved body parts and wreckage, including part of an engine, some of which have already been taken to Jakarta. Flight tracking and specialist air crash sites have already revealed some information about the flight, the departure of which had been delayed by heavy rain. SEE: AR’s Geoffery Thomas talking about the crash on the BBC and ABC The Aviation Herald reported the aircraft had departed Soekarno International Airport at 2:36 pm local time, climbed through 1700 feet and was cleared to 29,000 feet. “Departure control subsequently noticed that the aircraft was not on its assigned heading of 075 degrees, but tracking northwesterly and queried the crew about the heading at 14:40L, but received no reply, within second(s) the aircraft disappeared from radar,” it said. Flightradar24 ADS-B data showed the 737 departed on runway 25R and was climbing through 10,600 feet at 2:39:50 pm local time about 11nm north of Soekarno airport then lost 10,000ft of altitude in less than a minute. Authorities have said damaged engine parts indicate the aircraft was still functioning down to 250ft.