The details were presented at a news conference in Taipei by Aviation Safety Council Executive Director Thomas Wang as preliminary findings based on the flight data recorder.
Wednesday's crash into a river in Taipei killed at least 35 people and left eight missing. Fifteen people were rescued with injuries.
Wang said the plane's right engine triggered an alarm 37 seconds after takeoff. However, he said the data showed it had not shut down, or "flamed out" as the pilot told the control tower, but rather moved into idle mode, with no change in the oil pressure.
Wang said it was too early to draw firm conclusions about the reasons why the engines ceased producing power. "It's only the third day so we can't say too much," Wang said. "We haven't ruled anything out.