What happened
On a scheduled passenger flight from Ottawa to Halifax, a Boeing 737, registration C-FGCJ, performed an ILS approach to Runway 15 under low visibility conditions. During the descent, the crew encountered a cloud ceiling of approximately 100 feet and a runway visual range of 2200 feet. As the aircraft approached the runway, the captain took control of the aircraft at 100 feet above ground level after the first officer did not respond to a verbal correction regarding the aircraft's position relative to the centerline. At this altitude, a strong wind gust from the right caused the aircraft to drift left.
Upon touchdown, the aircraft's heading shifted significantly to the right of the runway heading. The crew applied reverse thrust, but a subsequent strong gust caused the aircraft to continue drifting toward the left edge of the runway. The captain attempted to correct the track using right rudder, differential braking, and nosewheel steering. Directional control was eventually regained by reducing the reverse thrust on both engines to the idle detent and applying right differential braking. The aircraft stopped on the runway, and passengers were deplaned without 0 injuries.
The investigation
The TSB examined the runway conditions, the aircraft's mechanical state, and the flight data. Investigators found that Runway 24, which features superior lighting, was unavailable due to flooding caused by heavy rain and a collection pond overflow. The runway surface for Runway 15 was reported as bare, wet, and partially covered in compact snow.
Technicians also discovered that the aircraft was equipped with an incorrect Flight Data Recorder (FDR) model, which only recorded four parameters instead of the required 18. While the aircraft systems were functioning normally and no hydroplaning was detected, the investigation focused on the interaction between the wind, the runway surface, and the crew's control inputs.
Findings
- The crew's ability to detect and correct the aircraft's drift was hindered by ground fog that degraded visual cues during the final moments of the approach.
- The loss of directional control was likely caused by a combination of aircraft drift, reverse thrust, strong gusting crosswinds, and the wet runway surface.
- The recovery of directional control may have been delayed because the captain continued to apply maximum right wheel braking throughout the excursion.
- The unavailability of Runway 24 prevented the use of a runway with superior approach and centerline lighting.
- The installation of an incorrect FDR model limited the amount of flight parameter data available for analysis.
Safety action
- The operator replaced the incorrect FDRs with approved models and implemented a new inspection and audit system for spare parts.
- The Halifax International Airport Authority upgraded the drainage system for Runway 24 and installed a water level alarm and remote pump controls to prevent future flooding.