The investigation into the crash of the SSJ 100, which, on May 9, cost the lives of its 45 occupants during a demonstration flight in Indonesia, is closed.
After analysis of the information obtained from the black boxes, we now know precisely what happened during the last minutes of flight RA 36801.
At 02:20 PM local time, the Sukhoi takes-off from Jakarta airport, runway 6, and four minutes later, the aircraft reaches its cruising altitude of 10,000 feet. At 02:26 PM, the pilot asks the control tower to descend to 6,000 feet by making a right turn. The request is accepted. And then, the following sequence, where everything speeds up.
After less than six minutes of descent, the alarm indicating a terrain awareness and warning system (TWAS) starts to sound in the cockpit, then it’s the turn of the warning "Avoid terrain" heard six times, but the pilot thinks it’s a data problem and de-activates the warning system. At 02:32 PM, 38 seconds after the first alarm, the SSJ 100 slams into Mount Salak, at 5,900 feet; but the aircraft disappears from radar screens only 18 minutes later.
The tragedy could have been avoided if remedial action had been initiated within 24 seconds after the first warning. Human error was therefore the cause of the accident. The pilots were not informed of the mountainous region over which they would fly, which led them to deactivate the alarm, and were further distracted by the presence of potential customers in the cockpit. Air traffic controllers in Jakarta and the lack of terrain data have also been singled out. The technical characteristics of the Russian regional aircraft are therefore not in question, and the SSJ 100 programme can continue, and be exported abroad.