Incident Overview
On the day of the occurrence, Bearskin Lake Air Service Flight BLS342, a Fairchild Metro SA227-AC (registration C-FYAG, serial number AC-670B), was conducting a flight from Kenora, Ontario, to Dryden, Ontario. The aircraft landed on Runway 11 at Dryden at 1457 central standard time in daylight conditions, with two pilots and ten passengers on board. During the landing roll, the aircraft yawed to the left immediately at touchdown and departed the left side of the runway, traveling approximately 150 feet through snow before coming to rest. The aircraft sustained no structural damage, though two tires on the left main landing gear were blown. No injuries were reported among crew or passengers.
Flight and Crew Details
The crew had flown several uneventful flights in C-FYAG earlier that day, landing in Kenora at 1412. Following de-icing at Kenora, a higher than usual power setting was required to get the aircraft rolling because one or more brakes had frozen during de-icing. The brakes operated properly during the taxi check and subsequent before-landing check. The crew followed the Bearskin Airlines Metro SA227 Standard Operating Procedures (SOP) to reduce the risk of brake freeze-up but took no additional action to mitigate the risk of loss of directional control on landing, as the SOP and Airplane Flight Manual did not require such action. The first officer was the pilot flying for the approach and landing.
Landing and Runway Excursion
The aircraft touched down on the runway centerline in the normal touchdown zone at the correct speed and in the correct landing configuration. Immediately after touchdown, the aircraft yawed left. The first officer applied reverse thrust on the right engine and full right rudder. The aircraft was equipped with nosewheel steering (NWS), which was armed before landing but not engaged. The NWS engagement was not triggered because the crew did not select the speed levers to LOW while responding to the yaw, and the first officer did not press the power lever NWS engage switch due to already applying full right rudder. Centering the rudder pedals to engage the NWS would have worsened the yaw. Additionally, the first officer's foot position prevented application of the right brake while maintaining right rudder pressure. The yaw increased uncontrollably before the captain could assist, and the aircraft exited the runway about 2900 feet from the threshold. The engines were shut down and propellers feathered before departure from the runway.
Post-Incident Actions
After the aircraft stopped, passengers were evacuated through the main door after confirming no injuries. An airport maintenance equipment operator observed the incident and notified Winnipeg Radio, then drove to the site to confirm that emergency services were not required. The evacuation was directed by the first officer, but passenger movement after exiting was not directly controlled; most walked to the terminal. The aircraft was towed to a hangar later that evening after maintenance personnel thawed frozen brake units on both main landing gear using a portable heater. TSB investigators examined the aircraft the following day and found no anomalies in the brake system, parking brake, or NWS. The left main gear tires had large flat spots with holes through the tread and cords; right main gear tires were undamaged.
Weather and Runway Conditions
At the time of the occurrence, Dryden weather was reported as wind 080° True at 10 knots, visibility two statute miles in light snow, overcast ceiling at 1100 feet, temperature -18°C. The runway at Dryden had been inspected earlier, with surface conditions including 20% bare and dry, 80% loose snow ¼-inch depth, and a Canadian runway friction index of 0.38. Airport snow removal was ongoing throughout the day, and equipment operators vacated the runway shortly before landing. After the incident, a post-occurrence inspection confirmed the runway was debris-free.
Aircraft and Systems Examination
Both the cockpit voice recorder and flight data recorder (not required by regulation but installed) were removed and sent for analysis. The aircraft was certified, equipped, and maintained in accordance with regulations, and the flight crew were certified and qualified. No deferred maintenance items were relevant. The runway strip, graded with gravel, fulfilled its intended purpose of reducing damage risk. No tire skid marks were found on the runway surface.