DE HAVILLAND DHC-8, SEATTLE, WASH., JAN. 19, 2004–At 11:38 a.m. the flight crew of Dash 8 C-GTAQ inadvertently landed on a taxiway at Seattle-Tacoma International Airport (SEA). There were no injuries to the captain, first officer, flight attendant or any of the 32 passengers, nor was there any damage to the aircraft, which is owned and operated by Air Canada Jazz. The Part 129 scheduled airline flight, which had left Vancouver, British Columbia, about 45 minutes before the incident, was landing in VMC and was on an IFR flight plan.
According to the crew, they were cleared by Seattle Center for a visual approach to Runway 16R. When they were near Elliot Bay, the crew contacted Seattle-Tacoma Tower and were cleared to land on Runway 16R, number two behind a 737 that was then touching down. Neither crewmember saw the 737. The captain, who was flying at the time, therefore aligned the aircraft with what he felt sure was Runway 16R. He then continued on the approach and completed what to him seemed to be an uneventful landing. Soon after touchdown, the tower advised the flight crew that they had landed on Taxiway Tango.
The captain said that when they lined up on final approach, there was an overcast over the approach end of the runway, bright sunshine to the south of the airport and glare on the runway surface. According to him, this caused the area around the approach end of the runway to appear as one dark color, making it hard to differentiate between the runway and the taxiway. He said that he had been into SEA many times before and was aware of the large X just off the north end of Taxiway Tango. But because of the contrast between the runway glare and the dark area around the approach end, he did not notice that he had flown over the X just before touchdown.
In a later discussion with the NTSB investigator in charge, the captain said it was his opinion that lights on the X and spaced-interval visual clues painted on the taxiway would probably have alerted him to the misidentification of the landing surface in time to execute a safe go-around.