Transport Minister Jonan on Tuesday gave the first detailed information about the final minutes of Flight QZ8501 based on radar data. Data from the black box flight recorders would give a more detailed picture, Kurniadi said.
At 6:17 a.m. on Dec. 28, three minutes after air traffic control unsuccessfully tried to make contact and asked nearby aircraft to try to locate QZ8501, the A320 turned to the left and it began to climb from its altitude of 32,000 ft (9,750 meters), Jonan told a parliamentary hearing.
The rate of the climb increased rapidly within seconds to 6,000 ft a minute, before accelerating further to 8,400 ft a minute and finally 11,100 ft. The aircraft reached 37,600 ft just 54 seconds after it began to climb before it appeared to stall.
The aircraft began to fall at 6:18 a.m., dropping 1,500 ft in the first 6 seconds before reaching a rate of descent of 7,900 ft per minute until it reached 24,000 ft, at which point it disappeared from the radar.
Pilots and industry observers told Reuters that if an aircraft makes a rapid climb and start to lose speed, it would be likely to stall and suffer from a loss of control.
Based on Jonan’s data, there did not appear to have been a controlled descent in the case of QZ8501 and the aircraft appeared to have fallen rapidly before crashing into the sea, they added.
Bad weather in the area has been cited a possible factor in the crash, with the other aircraft close by at that time flying at altitudes of between 34,000 and 39,000 ft.
The investigators were looking into why this was the case, as well as QZ8501 pilots’ reaction to the storms and clouds in the area, according to a source close to the investigation.
Industry experts say that the margin for error at higher altitudes is smaller than at take-off or lower down.
While the A320’s systems usually prevent pilots from doing anything outside usual safe flight parameter, these protections can be disabled in some circumstances, handing control to the pilots and leaving it to manual flying skills.