An update today (from Avherald):
On May 24th Russia's Rosaviatsia (Civil Aviation Authority) released a report dated May 22nd stating that a descent from the mountaineous area's minimum safe altitude of 10,000 feet to 6,000 feet had been pre-arranged. The flight was continued at 6,000 feet until the aircraft impacted a slope rising up to 7254 feet MSL. The investigation is ongoing in all directions with a controlled flight into terrain (CFIT) being a likely scenario. Rosaviatsia reported that CFIT accidents typically are the result of one or more of the following factors:
- Execution of flight below safe altitude as result of deliberate action of the crew or loss of situational awareness
- Lack of response by the crew to (GPWS/TAWS) alerts of terrain closure
-Clearance by ATC to descend in mountaineous terrain in absence of accurate position data
-Erroneous altitude indications due to incorrect pressure setting or system malfunction.
Sukhoi later added, that based on preliminary analysis of the cockpit voice recorder data a paper was signed by both Indonesia's National Transportation Safety Committee and Russia's Interstate Aviation Committee investigation the crash. The paper stated that no system malfunctions were detected prior to impact, the aircraft's Terrain Awareness and Warning System (TAWS) was operating and provided the crew with information about hazardeous ground proximity.