What happened
On June 16, 2010, at approximately 14:30 EDT, a United Express flight operated by Trans States Airlines, an Embraer EMB-1rag5LR with registration N847HK, overran Runway 07 at Ottawa/MacDonald-Cartier International Airport. The aircraft, carrying 33 passengers and 3 crew members, was arriving from Washington Dulles International Airport.
During the landing, the aircraft touched down on a wet runway and experienced a period of floating before the nose wheel made contact with the ground. Despite the application of maximum braking by the crew, the aircraft failed to decelerate sufficiently. The jet remained on the centerline until roughly 200 feet from the runway end, at which point it veered left and exited the paved surface. The nose gear collapsed as the aircraft traveled through the grass, eventually coming to a stop 550 feet beyond the runway end. The incident resulted in 3 minor injuries and substantial damage to the aircraft's nose and cockpit area.
The investigation
The investigation examined the aircraft's mechanical systems, including the digital brake-by-wire system, the antiskid function, and the landing gear. Testing of the braking components and tires revealed no mechanical failures or malfunctions. Investigators also analyzed the flight data recorder (FDR) and reviewed the flight crew's recent duty history, noting that both pilots had experienced significant sleep deprivation due to flight delays and early commutes.
Performance calculations performed by Embraer indicated that, given the landing weight and environmental conditions, the aircraft should have been able to stop within the available runway length if it had possessed thrust reversers. The investigation also looked into the runway's physical characteristics, specifically the transverse slope and drainage capabilities.
Findings
- The aircraft was not equipped with thrust reversers, which significantly increases the risk of overruns on wet runways.
- The lack of thrust reversers was a primary factor in the inability to stop the aircraft on the contaminated surface.
- Discrepancies were noted in the friction coefficient values used in regulatory calculations compared to real-world performance on wet runways.
- The runway's transverse slope did not meet recommended practices for rapid water drainage, contributing to the slippery conditions.
- The flight crew was operating under conditions of fatigue due to insufficient rest following a delayed duty day.