“They are pilots,” he said. “They are professional.”

Mr. Sirait also said that he had no information about what may have caused the Flight 610 crash. “I am not an engineer,” he said.

Many aviation experts are skeptical of the company. “Lion’s corporate culture is against safety,” said Mr. Lie, the ombudsman. “If they can fly the plane, they will, rather than ground it and figure out what the problem is.”

During the two days before Flight 610 began its final journey, there were repeated indications that pilots were being fed faulty data — perhaps from instruments measuring the speed and a key angle of the plane — that would have compromised their ability to fly safely.

Engineers tried to address the issue in at least three airports, Indonesian investigators said.

After the plane’s penultimate flight, for instance, technicians recorded in a maintenance log that they had fixed the pitot tubes, external probes on the airplane that measure relative airspeed. Earlier that day, on the resort island of Bali, engineers swapped out a sensor that measures the angle at which oncoming wind crosses the plane.

Called the angle of attack sensor, this instrument tells the pilot if the nose of the plane is too high, which could cause the aircraft to stall. In the Max 8, if the data indicates the nose is too high, the aircraft’s systems will automatically pull the nose down.

If the sensor data is wrong, the system could cause the plane to dive.

It is not yet certain if the airspeed sensors and angle of attack sensors malfunctioned on the final flight, or if the computers that process the information coming from the censors malfunctioned.

It is only with further analysis of data on the plane’s so-called black boxes, of which only one has been found, that the cause will be determined.