Crew members of Crest Onyx ship prepare to unload parts of AirAsia Flight 8501 from a ship at Kumai port in Pangkalan Bun,Sunday, Jan.11, 2015. A day after the tail of the crashed AirAsia plane was fished out of the Java Sea, the search for the missing black boxes intensified Sunday with more pings heard. AP
JAKARTA, Indonesia 鈥� Indonesia鈥檚 top accident investigator said Wednesday that there are no indications of foul play in last month鈥檚 crash of an AirAsia jetliner carrying 162 people.
AirAsia Flight 8501 plunged into the Java Sea on Dec. 28 shortly after the pilots asked to climb from 32,000 feet to 38,000 feet to avoid threatening clouds, but were denied permission because of heavy air traffic. No distress signal was received. The plane was en route from Surabaya, Indonesia鈥檚 second-largest city, to Singapore.
鈥淭here is no sign of sabotage in the AirAsia crash,鈥� National Transportation Safety Committee head Tatang Kurniadi told reporters.
He said investigators have downloaded all of the data from the aircraft鈥檚 cockpit voice recorder and flight data recorder and are analyzing them along with advisers from Airbus, the plane鈥檚 manufacturer.
One of the committee鈥檚 investigators, Nurcahyo Utomo, said Tuesday that no voices have been detected on the cockpit voice recorder other than those of the pilot and co-pilot, and no explosions were heard.
Transport Minister Ignasius Jonan told Parliament on Tuesday that radar data showed that the plane was climbing at an abnormally high rate 鈥� about 6,000 feet a minute 鈥� then dropped rapidly and disappeared.
鈥淚t is not normal to climb like that, it鈥檚 very rare for commercial planes, which normally climb just 1,000 to 2,000 feet per minute,鈥� he said. 鈥淚t can only be done by a fighter jet.鈥�
He did not say what caused the plane to climb so rapidly.
An excessively rapid ascent is likely to cause an airplane to go into an aerodynamic stall. In 2009, an Air France Airbus A330 disappeared over the Atlantic Ocean in bad weather while flying from Rio de Janeiro to Paris. Investigators determined from the jet鈥檚 鈥渂lack boxes鈥� that it began a steep climb and then went into a stall from which the pilots were unable to recover.
Airbus spokesman Justin Dubon said Tuesday that it was too early to comment on possible similarities between the two crashes.
Kurniadi said a preliminary report on the AirAsia accident is expected to be submitted to the International Civil Aviation Organization next week, in line with a requirement that it be filed within 30 days of a crash. But he said a full analysis of what went wrong with the plane could take up to a year.
Rescuers are struggling to lift the fuselage and what appears to be the plane鈥檚 cockpit from the seabed at a depth of 30 meters (100 feet). The search has been complicated by strong currents, high waves and bad weather. Only 53 bodies have been recovered so far.