The light propeller plane that crashed into a residential area in Chofu, Tokyo, on Sunday was already unstable immediately after takeoff as it faltered, tipping from side to side, according to sources from the transportation ministry and investigative authorities. The crash killed or injured eight people.
An airplane's body is said to be unstable when it does not have sufficient power. The Metropolitan Police Department believes the plane did not have enough lift because it failed to reach adequate speed for takeoff due to engine or some other trouble affecting its body during the takeoff run.
The MPD began searching Nippon Aerotech Co., the company that managed the plane, on Tuesday. Earlier in the day, the MPD also announced it confiscated some materials such as part of what appears to be the frame of the main wing of the plane when the on-site inspection was held on Monday. Instrument parts and the engine were also found at the crash scene, a MPD senior official said. The engine was almost completely intact, according to the official. The MPD will collect the items to investigate the cause of the accident in detail.
According to the sources, the plane was slightly faltering, tipping from side to side right after it lifted off after the takeoff roll, then tilted to the right and flew to the left. The series of movements was mainly confirmed through video footage which caught the plane during the takeoff roll and after, the sources said.
Even if a plane is having such problems as engine trouble during the takeoff roll, aviation rules call for takeoff to continue if the pilot judges the aircraft cannot stop safely.
According to the sources, the plane ran almost to the end of the runway. "It possibly had trouble during the takeoff roll, and it avoided running off the end of the runway by taking off, but stalled as it couldn't increase its altitude," a source said.