Jakarta: Indonesia was set to publish the results of its investigation into last year`s crash of an Indonesia AirAsia passenger jet on Tuesday, the first official explanation to the families of the 162 people killed in the disaster.
The Airbus A320 crashed into the Java Sea on Dec 28 last year, less than halfway into a two-hour flight from Indonesia`s second-biggest city of Surabaya to Singapore.
It is one of a string of aviation disasters in Southeast Asia`s biggest economy where rapid growth in air travel has overcrowded the country`s airports and raised safety concerns.
The report, to be released around 0700 GMT, is expected to offer the first official explanation of why flight QZ8501 disappeared from radar, after the Indonesian Transportation Safety Committee declined to publish its preliminary report.
Among the facts released so far, the French first officer was at the controls just before the accident and a stall warning sounded in the cockpit, indicating that the jet had lost lift.
The report is expected to focus in particular on whether any of the airplane`s systems were faulty and how pilots responded.
People familiar with the matter told Reuters earlier this year that investigators were examining maintenance records of a key part of the aircraft`s control systems.
According to reports, one of the pilots attempted to shut power off to the intermittently faulty computer by pulling circuit-breakers, a procedure not usually allowed in flight.
Two sources told Reuters that the captain appeared to have left his seat in order to do so, but Indonesian investigators said in February they had not found evidence for this or that power was deliberately shut off.
Experts say an outage of the so-called Flight Augmentation Computers would not directly cause the plane to crash, but without them pilots would have to rely on manual flying skills that are often stretched during a sudden airborne emergency.
The report is not designed to attribute blame but to make recommendations to avoid future accidents.
AirAsia Chief Executive Tony Fernandes has vowed to support the investigation and said in August the group had already ordered a review of its systems following the crash.
Indonesia has seen two other major crashes in the past year including a military cargo aircraft that went down in an urban area in northern Sumatra in July, killing over 140 people on board and on the ground and prompting the air force to review its ageing fleet.
Its handling of the high-profile investigation may be scrutinised by regulators in the European Union, where a majority of its airlines are banned from flying due to concerns about safety regulation. Indonesia AirAsia and flag carrier Garuda are not on the EU`s so-called `blacklist`.