WASHINGTON — The captain of an airliner that ran off a runway in Denver during a strong crosswind could have prevented the accident if he had used the plane’s rudder to correct its direction, federal safety investigators said Tuesday.
The captain had a lot of flying experience and a good safety record, but he had probably never attempted a takeoff in crosswinds as strong as he faced the evening of Dec. 20, 2008, investigators told the National Transportation Safety Safety Board. Nor had he been trained for gusts that high, they said.
The Continental Airlines Boeing 737 with 110 passengers and five crew members was in the midst of a takeoff roll at Denver International Airport when it suddenly veered left off a runway, rumbled across a frozen field, broke into pieces and burned. No one was killed, but six people were seriously injured and dozens more were treated for minor injuries.
Just before the plane left the runway there was a gust of 52 mph that, hitting the plane’s tail, caused it to “weathervane” — turn until its nose was pointed into the wind, investigators said.
The pilot had twice applied the plane’s right rudder during the first 12 seconds of the takeoff roll to correct its direction back to the right. But when a gust caused the plane to swing violently to the left, he reached instead for the tiller — which turns the nose wheel and was of no use under the circumstances — instead of reapplying the rudder to turn the plane back to the right, investigators said.
The board was meeting to determine the cause of the accident and make safety recommendations.
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.
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 in written comments to the board.
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.
Continental’s guidance to pilots flying 737s was not to take off in crosswinds greater than 38 mph.
“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.