The Federal Aviation Administration, which released the data, said the increase is because of the way errors are reported and categorized, but critics point to alleged problems, including inexperienced staffers and training inadequacies, The Boston Globe reported Monday.
Congress has asked for a Department of Transportation investigation, and a DOT report is expected in the spring.
While the FAA says American aviation has had its safest period ever, a spokeswoman acknowledged concern about the rise in controller errors.
Federal aviation officials are "reviewing procedures and training throughout the air traffic control system to ensure we are addressing any safety issues and making any necessary changes," Arlene Salac told the Globe.
Half of the country's 15,000 air traffic controllers have been hired in the past five years as the FAA scrambles to replace a large number of retiring controllers, and on any given day up to 25 percent of controllers on duty are trainees, the Globe reported.