NTSB Factual Report

On August 29, 2005, approximately 1409 Pacific daylight time, an Airbus A330-223, N855NW, was taxiing for takeoff when it collided with a Bombardier DHC-8-202, N363PH, that was standing with engines operating waiting to be marshaled to its parking spot on the Portland International Airport, Portland, Oregon. There were no injuries to the 3 flight crewmembers, 9 flight attendants, and 235 passengers aboard the Airbus or to the 2 flight crewmembers, 1 flight attendant, and 20 passengers aboard the Bombardier. There was minor damage to the left winglet of the Airbus and substantial damage to the tail of the Bombardier. The Airbus was operated by Northwest Airlines as flight number 5, a 14 CFR Part 121 scheduled international passenger flight from Portland to Narita Airport, Japan. The Bombardier was operated by Horizon Air as flight number 2066, a 14 CFR Part 121 scheduled domestic passenger flight from Medford, Oregon to Portland. Visual meteorological conditions prevailed, and instrument flight rules flight plans were filed for both flights.

According to information provided by FAA inspectors who responded to the scene of the accident, the Airbus was taxiing east via Taxiway B to runway 28L for departure. The Bombardier had landed, taxied to the gate area, and was stopped on the ramp located north of Taxiway B waiting to be marshaled to its parking spot. The Bombardier was sitting on a northerly heading, oriented perpendicular to Taxiway B with its tail towards the taxiway. As the Airbus passed behind the Bombardier, the left wingtip of the Airbus struck the tail of the Bombardier. The left winglet of the Airbus was scraped, bent and cracked. The vertical stabilizer, horizontal stabilizer, both elevators, and the rudder on the Bombardier sustained structural damage.

Portland Air Traffic Control Tower prepared a chronological summary of the event and a transcript of the communications on the ground control frequency. The chronology indicated that at 1403, the Bombardier contacted ground control stating they had exited the runway at Taxiway B-5 for spot 14, and the ground controller cleared them to taxi to spot 14. At 1405, the Airbus advised they were ready to taxi, and the ground controller instructed them to taxi to runway 28L. The transcript indicated that at 1406:40, the ground controller advised the Airbus to "use caution for a dash eight [Bombardier] pulled up ah on taxiway tango by bravo ahead and to your left should have wing tip clearance there." The Airbus acknowledged the transmission. At 1408:58, the unidentified transmission, "hey ah northwest are you (unintelligible)" was made. At 1412:45, the Airbus advised the ground controller that they had hit the Bombardier.

During an interview conducted by FAA inspectors, the captain of the Bombardier reported that the flight's landing and taxi in were normal. He further reported that the flight was instructed to park in spot 14, and he held on the ramp short of the spot awaiting a marshaler to direct him into the parking spot. While waiting to be marshaled, the captain heard the ground controller direct the Airbus to taxi behind his airplane. He then taxied his airplane "as far forward as possible but did not cross the access road due to the missing marshaler." The captain reported that the Bombardier was stopped when the Airbus passed behind it. Just prior to the impact, the captain attempted to contact the ground controller, but the impact pulled his hand away from the radio transmit switch. Following the event, the flight crew shut down the engines, and the passengers exited the Bombardier and walked to the terminal. There was no emergency evacuation.

According to a written statement submitted by the captain of the Airbus, the flight was cleared to taxi to the runway, and the ground controller commented that the flight should "not have a problem" getting past the Bombardier that was clear of the taxiway on the ramp. The captain reported that the tail of the Bombardier "appeared to be 20-30 feet outside the taxi line" and that he was "not comfortable" with the Bombardier's position. As the Airbus approached the Bombardier, the Bombardier "moved forward about another 20-30 feet perpendicularly away from the yellow taxiway edge line." The captain asked the augmenting captain seated in the jump seat if it looked like they would clear the Bombardier, and the augmenting captain got out of his seat and looked out the left window. The augmenting captain told the captain that it looked like he would have 10-20 feet of clearance. The captain reported that he also looked at the left wingtip and thought there was adequate clearance. According to the captain, the nose wheel of the Airbus was slightly right of the taxiway centerline when he passed behind the Bombardier. The captain felt a "shudder" and stopped the airplane. Following the event, the Airbus taxied back to the gate, and the passengers de-planed. Written statements submitted by the first officer and the augmenting captain of the Airbus collaborated the captain's statement.

When FAA inspectors reached the scene, the Airbus was parked at the gate, and the Bombardier had not been moved since the collision. FAA inspectors measured the distance between the Bombardier's nose wheel and the centerline of Taxiway B as approximately 150 feet. According to information provided by Horizon Air, the distance from the nose wheel to the tip of the Bombardier's tail was approximately 67 feet. This placed the tip of the Bombardier's tail approximately 83 feet from the centerline of Taxiway B. According to information provided by Northwest Airlines, the wingspan of the Airbus was 197 feet 10 inches. With the nose wheel of the Airbus on the centerline of the taxiway, the tip of the left wing would have been located 98 feet 10 inches left of the centerline.

NTSB Probable Cause

The failure of the flight crew to maintain adequate clearance while taxiing.