Federal investigators issue first recommendations following Hudson crash

By Mike Ahlers
CNN
WASHINGTON (CNN) - When Canada geese were sucked into the engines of his Airbus A320, Capt. Chesley "Sully" Sullenberger didn't have time to switch a radio code to indicate an emergency.

Now federal accident investigators are recommending a change that could help in similar situations: letting air traffic controllers make the switch from the ground.

The recommendation by the National Transportation Safety Board is the first resulting from its investigation into the January 15 incident, in which Sullenberger and his crew safely landed their jetliner in the Hudson River and evacuated all 150 passengers.

The safety board has praised the crew and air traffic controllers for their actions, but it said Wednesday that technological changes may help in future emergencies.

The board wants air traffic controllers to be able to change signals coming from airplane's transponders - devices that emit signals identifying an aircraft and giving its altitude and ground speed.

During Sullenberger's flight, the aircraft appeared on some radar screens simply as the letter "L," indicating that LaGuardia Airport departure controllers were responsible for tracking the plane, according to the safety board. The "L" was not accompanied by what is known as a "data block," which would have included the aircraft's call sign (AWE1549) and other information.

Because Sullenberger was attending to the loss of both engines, "he did not switch the airplane's transponder to emergency code 7700 nor was he required to do so," the safety board said.

The controller could have asked the pilot to change the code, but he "did not want to add to the pilot's workload," it said.

Had the 7700 code been transmitted, the data block of information would have automatically been displayed on all radar scopes within range, along with a flashing "EM" tag indicating an emergency, the safety board said. Such additional information could help other controllers quickly locate a troubled aircraft and might be useful in helping a plane out of its predicament.

In the case of Sullenberger's aircraft, departure controllers at LaGuardia saw the data block, but some other controllers who would next handle the airplane saw only the "L."

The safety board is recommending that the radar system be modified so that air traffic controllers can instruct it to process the transponder code, changing it to an emergency code. The board said that preliminary discussions with the Federal Aviation Administration's technical staff indicates the change is possible.

The safety board recommendation takes pains not to criticize Sullenberger, who has become a national hero. Nor does it criticize the actions of his crew or the air traffic controllers, all of whom were praised during a Capitol Hill appearance soon after the crash.

The board noted that as soon as the pilot advised the departure controller that he was trying to return to the airport for an emergency landing, the departure controller contacted the LaGuardia tower controller and told him, "Stop departures. We got an emergency returning."

The departure controller "did not provide the call sign, type, or location of the aircraft that was declaring the emergency," the board said.

"During interviews with NTSB investigators, the departure controller said that he did not provide a location for the accident airplane because it had just departed and he believed the full data block was still being displayed on the LGA (LaGuardia) controllers' radar displays," the safety board said.

The LaGuardia controllers were not able to locate the plane, it said, until the triggering of a "conflict alert" between the plane and another aircraft caused the data blocks for both aircraft to be displayed.

Doug Church, a spokesman for the National Association of Air Traffic Controllers, welcomed the safety board's action.

"This recommendation does make sense and it is, in fact, practical and a good idea to enhance aviation safety," he said.

"It is technologically possible to implement the NTSB's recommendations," he said. "The benefit for controllers is that everyone in the facility, especially in adjoining sectors of airspace where the emergency is taking place, would know at the same time that there is an emergency aircraft in the facility's airspace that is receiving attention. It would stand out on everyone's scopes."