PANGKALAN BUN, Indonesia (AP) — Underwater ping-like sounds were heard Friday in an area where searchers are scouring the Java Sea for the crashed AirAsia plane, but it was unclear if they were coming from the all-important black boxes, an official said.
The signals were picked up intermittently, but no metal was detected at the location, said Suryadi B. Supriyadi, the National Search and Rescue Agency's operational director.
Nurcahyo Utomo, a National Commission for Transportation Safety investigator, said the sounds could not be confirmed.
A day earlier, photos and video confirmed that part of the plane's tail had been found on the seabed — the first major wreckage seen since Flight 8501 went down Dec. 28 with 162 passengers and crew on board.
The cockpit voice and flight data recorders are located in the rear, but Supriyadi said the pings were heard about a kilometer (half mile) from the site of the tail. It was possible the signals were coming from another source.
Officials were hopeful that the black boxes remained in the plane after the impact, and plan to hoist the tail from the seabed.
They are key to helping investigators understand what caused the Airbus A320 to go down about halfway into its flight from Surabaya, Indonesia, to Singapore.
The last contact the pilots had with air traffic control indicated they were entering stormy weather. They asked to climb from 32,000 feet (9,753 meters) to 38,000 feet (11,582 meters) to avoid threatening clouds, but were denied permission because of heavy air traffic above them. Four minutes later, the plane dropped off the radar.
Four additional bodies were recovered Friday — two of them still strapped in their seats on the ocean floor — bringing the total to 48. Officials hope many of the remaining corpses will be found inside the fuselage, which has not yet been located by divers. Several large objects have been spotted in the area by sonar.
Though the water is relatively shallow at about 30 meters (100 feet) deep, this is the worst time of year for a recovery operation because of monsoon rains and wind that create choppy seas and blinding silt from river runoff.