Carrying 97 passengers and a crew of seven, the Boeing 737 departed Jakarta’s Soekarno-Hatta International Airport’s runway 25R at 15:37 local time (08:37 UTC) for a planned 80-minute flight to Singapore Changi Airport, with captain Tsu Way Ming (朱卫民), 41, of Singapore, a former A-4 Skyhawk pilot, at the controls along with first officer Duncan Ward, 23, of New Zealand. Generally fair weather was expected for the route, except for some thunderstorms near Singkep Island, 120 km (75 mi) south of Singapore.

Flight 185 remained level at FL350 until it started a rapid and nearly vertical dive around 16:12. While descending through 12,000 ft (3,700 m), parts of the aircraft, including a great extent of the tail section, started to separate from the aircraft’s fuselage due to high forces arising from the nearly supersonic dive. Seconds later, the aircraft impacted the Musi River, near Palembang, Sumatra, killing all 104 people on board. The time it took the aircraft to dive from cruise altitude to the river was less than one minute. The plane was travelling faster than the speed of sound for a few seconds before impact. Parts of the wreckage were embedded 15 feet into the riverbed.

The aircraft broke into pieces before impact, with the debris spread over several kilometres, though most of the wreckage was concentrated in a single 60-metre (200 ft) by 80-metre (260 ft) area at the river bottom. No complete body, body part or limb was found, as the entire aircraft and passengers disintegrated upon impact. Only six positive identifications were later obtained from the few recovered human remains.