What happened
The flight crew initiated engine operations with specific procedural deviations that contributed to the incident. The captain started the right engine while the aircraft was at the gate. Subsequently, the left engine was started while the aircraft was taxiing for takeoff. During this phase, the first officer was occupied briefing passengers on takeoff and en route procedures.
The first officer then initiated the takeoff roll. As the aircraft accelerated down the runway, it proceeded to the left side of the pavement. The aircraft struck a runway light during this maneuver.
The investigation
Post-incident examination revealed the mechanical cause of the failure. Investigators found that the left propeller was still engaged on the start locks. This condition prevented the propeller from feathering or operating correctly during the takeoff sequence, leading to the asymmetric thrust and control issues that caused the runway excursion.