A Metro 23 operated by Perimeter Aviation as flight Bearskin Airlines 344, was conducting a VFR flight from Dryden Regional (CYHD), ON to Sioux Lookout (CYXL), ON with 2 crew members and 6 passengers on board. As the aircraft started the takeoff roll on runway 12, the aircraft directional control was lost and the aircraft exited the right side of the runway. The propellers subsequently contacted a snow bank and broke apart. Parts of the broken propellers penetrated the fuselage, injuring 1 passenger. The aircraft was substantially damaged. A similar accident occurred to a Skylink Charter Metro III on 29 September 2002. The aircraft, N343AE, veered off the runway on takeoff from Hawthorne Airport, California because one of the propellers was not out of the start lock. Findings as to causes and contributing factors 1. While the crew was carrying out the “Before Taxi” checklist, the “Start Locks” task was initiated; however, it was interrupted and not completed. 2. After the captain told the first officer to stand by, the crew’s focus shifted to other tasks. It is likely that this slip of attention resulted in the power levers not being pulled over the flight idle gate to release the start locks. 3. The “Before Taxi” checklist did not contain a task to ensure that the start locks were removed and, as a result, the crew began taxiing unaware that the propellers were still on the locks. 4. After the engine was started or while the occurrence aircraft commenced taxiing for departure, it is likely that slight or rapid transient movements of the engine power levers, which were needed to taxi the aircraft, resulted in the release of the left propeller start locks while the right propeller start locks remained engaged. 5. As the power was advanced through 20%, the “positive torque” call required by standard operating procedures was not made, and the engine torque differential was not noticed by the crew. As a result, power lever advancement continued although the right engine torque/thrust remained near zero. 6. The engaged start locks on the right propeller prevented forward thrust, which resulted in a significant thrust differential. This differential thrust during the take-off roll resulted in a loss of directional control of the aircraft and, ultimately, a lateral runway excursion. 7. Following the runway excursion, the propellers, which were operating at a high rpm, shattered and splintered when they struck a frozen snowbank. 8. High-energy release of the nickel-cobalt erosion strips and splintered wood core debris from the propeller blades penetrated the reinforcement panel, fuselage skin and cabin wall, and resulted in serious injuries to a passenger sitting next to the penetrated cabin wall