Makassar. Indonesian authorities believe an ATR 42-500 aircraft that crashed in South Sulawesi struck a hillside while still under pilot control, rather than suffering an engine failure, the head of the National Transportation Safety Committee said on Sunday.

Soerjanto Tjahjono, chairman of the committee, said preliminary findings — including a review of the final communications between the cockpit and air traffic control — showed no indication of malfunction in the aircraft’s flight control systems.

“The aircraft was controllable and could still be flown by the pilot. However, for reasons that remain under investigation, the aircraft struck a hill,” Soerjanto told a press conference at Sultan Hasanuddin International Airport in Makassar. “There was no problem with the aircraft’s controllability.”

The aircraft, operated by Indonesia Air Transport, was carrying 10 people, including seven crew members, when it went down on Saturday during a flight from Yogyakarta to Makassar.

Soerjanto said investigators are now focusing on the factors that caused the aircraft to deviate from its intended flight path and the sequence of events that led to the collision with terrain.

“We do not yet know the details, but one fact is clear: the aircraft struck a hill,” he said.

He also stressed that weather conditions should not be viewed as the sole cause of the accident, noting that weather is a variable typically anticipated through flight planning and mitigated by modern aviation systems.

Separately, search teams have located the aircraft’s emergency locator transmitter (ELT) in mountainous terrain in Balocci district, Pangkajene and Islands regency.

“In addition to the ELT, parts of the aircraft’s engine, along with documents and personal belongings of the crew and passengers, have been found. These discoveries have been reported to the National Search and Rescue Agency,” said Brigadier General Andre Clift Rumbayan, commander of the 141/Toddopuli Military Command overseeing the Sulawesi region.

The ELT was discovered about 700 meters from the summit of Mount Tompo Bulu at around 3 p.m. local time.

Evacuation efforts remain constrained due to the extreme terrain and adverse weather conditions at the crash site. Rumbayan said steep slopes and poor weather have significantly hampered search and recovery operations.

“The conditions at the crash location are extremely challenging, and unfavorable weather has further limited evacuation efforts,” he said.

Authorities said recovery operations will continue as weather and terrain conditions allow, while the investigation into the cause of the crash remains ongoing.