Bad weather and pilot error could have been the cause.

Pilot error is the most common cause of control reversal.

Pilot error was likely the cause, according to preliminary reports.

Following an investigation into the incident, Pilot error was found to be the main cause.

At the heart of the safety question is how much pilot error the system should tolerate.

Pilot error was determined to be the cause of the crash.

The final report states that pilot error had caused the accident.

On 26 May 2010, it was reported that pilot error had been identified as the reason for the crash.

The cause of the crash was determined as pilot error according to the official report.

The official report into the accident says it was caused by pilot error.