On 19 December 1997 , SilkAir Flight 185 , operated on a Boeing 737-300 and piloted by Captain Tsu Way Ming , plunged into the Musi River in Sumatra during a routine flight from Jakarta to Singapore , killing all 104 people on board . The crash was investigated by various groups , with different results . The Indonesian NTSC , who were lead investigators , stated that they were unable to determine the cause , while the US NTSB concluded that the crash resulted from an intentional act by a pilot , most likely the captain . A civil lawsuit case against Parker Hannifin , the manufacturer of the PCU-dual servo unit essential in the 737 's rudder control — and also suspected in causing the crashes of United Airlines Flight 585 and USAir Flight 427 under similar flight-event parameters , had provided the NTSB the initial test results of the recovered PCU-dual servo unit from Flight 185 in 1997 , but was later further independently investigated for litigation on behalf some families of Flight 185 passengers in a civil lawsuit against Parker Hannifin . The jury under the Superior Court in Los Angeles in 2004 , which was not allowed to hear or consider the NTSB conclusions , decided that the crash was caused by a prominent issue inherent in other 737 crashes : a defective servo valve inside the Power Control Unit ( PCU ) which controls the aircraft 's rudder , causing a rudder hard-over and a subsequent uncontrollable crash . The manufacturer of the aircraft 's rudder controls and the families later reached an out of court settlement . It is the first and only fatal hull loss for SilkAir
SilkAir Flight 185
SilkAir Flight 185
SilkAir