The cause of the crash remains disputed for the National Transportation Safety Committee, but the National Transportation Safety Board concludes the crash as a pilot suicide by the captain. But the Los Angeles Court thinks that the cause of the crash was a rudder malfunction.

The crash of SilkAir Flight 185 in December 1997 remains one of the most controversial cases in aviation history due to conflicting investigative conclusions. The Indonesian National Transportation Safety Committee (NTSC) officially stated that the cause was "inconclusive" and they were unable to determine the reason for the 737’s sudden, nearly supersonic dive into the Musi River. However, the U.S. National Transportation Safety Board (NTSB) disagreed sharply, concluding that the crash was the result of intentional pilot action, most likely by the Captain, who was believed to have manually disabled the flight recorders before maneuvering the plane into a terminal dive. In contrast, a later civil lawsuit in the U.S. resulted in a jury finding that a mechanical failure in the rudder's Power Control Unit (PCU) was responsible, a defect that had plagued other 737s in that era. To this day, the "official" cause remains a point of intense debate between those who cite pilot suicide and those who cite mechanical defect.