Feds probing silence in National Airport tower

Transportation Secretary Ray LaHood ordered Washington's Ronald Reagan National Airport to add an additional air traffic controller to its tower after two planes failed to receive radio responses as they tried to land at the airport Wednesday.

"I directed the FAA to place two air traffic controllers at Ronald Reagan Washington National Airport's control tower on the midnight shift," LaHood said in a statement. "It is not acceptable to have just one controller in the tower managing air traffic in this critical airspace. I have also asked FAA Administrator Randy Babbitt to study staffing levels at other airports around the country."

Two flights — a United Airlines flight from Chicago and an American Airlines plane from Dallas — had to land Wednesday evening without assistance from the flight tower at Reagan. There have been reports that the controller on duty might have been sleeping.

"The FAA is looking into staffing issues and whether existing procedures were followed appropriately," the Federal Aviation Administration said in a statement.

The National Transportation Safety Board has also said it would investigate the incident.