Denver air crash probe focuses on crosswinds

[July 13, 2010]  WASHINGTON (AP) -- Strong crosswinds are the focus of an investigation into why an airliner with 110 passengers ran off a runway in Denver, but the actions of air traffic controllers and the flight's captain have also been questioned, National Transportation Safety Board documents show.

The board is scheduled to meet Tuesday to determine the cause of the Dec. 20, 2008, crash of Continental Airlines Flight 1404. The plane was in its takeoff roll at Denver International Airport when it suddenly veered left off the runway, hurtled across a field, broke into pieces and was engulfed in flames.

No one was killed, but 37 people were injured.

The air traffic controller who cleared the plane for takeoff told pilots there was a crosswind of 31 mph, which was the reading on one of two wind sensors nearest the runway. However, the controller didn't mention that the other wind sensor was recording gusts of as much as 46 mph.

The gusts may actually have been as high as 52 mph, Continental said in comments filed with the board.

Controllers should have warned the flight's pilots about the gusts and changed the takeoff pattern at the airport to account for the wind, Continental said.

The Air Line Pilots Association, which represented the flight's captain during the investigation, also faulted controllers for not giving pilots the highest wind reading. But the union blamed the airport for not having enough wind sensors to adequately detect the gusty conditions encountered by the flight.

Boeing blamed the pilot in its comments to the board, saying the rudder wasn't manipulated correctly to compensate for the crosswinds.

The airline's guidance to pilots flying 737s was not to take off in crosswinds greater than 38 mph.

Depending upon the circumstances, a strong crosswind hitting the tail of a plane can cause it to "weathervane" -- spin around until it is pointing into the direction from which the wind is coming.

"Had the crew known of the actual current wind conditions as displayed on sensor No. 2, which exceeded Continental's ... guideline, they would have waited until wind conditions improved or requested a different runway," the airline said.

However, the National Air Traffic Controllers Association said the Denver controllers followed instructions by using the wind reading from the sensor that was closest to the departure end of the runway, which is where the plane leaves the ground and begins to climb. The union also said there isn't clear guidance from the Federal Aviation Administration on when controllers should change the direction of takeoffs and landings to account for strong winds.

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Online:

The National Transportation Safety Board http://www.ntsb.gov/

[Associated Press; By JOAN LOWY]

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