The Federal Aviation Administration said in a statement Tuesday that a preliminary inquiry indicates four flights were rerouted near Savannah, Ga., on Saturday.
"There was no compromise of safety by the rerouting," Kathleen Bergen, an FAA spokeswoman, said in an interview. Controller trainees "must train on simulators, but they must receive on-the-job training under the supervision of another fully certified controller and a supervisor before they can check out," Bergen said.
She said the FAA will investigate whether experienced controllers "were directed to reroute planes to generate additional traffic for the trainee, who was undergoing a skills check."
The FAA statement said the agency "has strict training guidelines which do not permit rerouting flights nor inconveniencing pilots or the flying public."
The aircraft were rerouted at the direction of a supervisor at the air traffic control center in Jacksonville, Fla., a controllers union official, Dave Cook, said. Four airliners operated by Delta, Virgin Atlantic and Southwest were detoured into an area between Jacksonville and Savannah, where there were reports of thunderstorms, he said.
The FAA denied there were thunderstorms in the region.
Cook, the National Air Traffic Controllers Association representative for the Jacksonville Air Route Traffic Control Center, said the rerouting increased the risk to the passengers and crews.
"In my 20 years as an air traffic controller we had never done anything like what they just did," he said.
Cook said the four planes - a Delta Boeing 757, a Virgin Boeing 747 and two Southwest Boeing 737s - were traveling south en route to Orlando International Airport near Wilmington, N.C., when they were rerouted inland on orders from an air traffic control supervisor who wanted to test the skills of a trainee.
The planes were directed at least 60-70 miles out of their way into an area of airspace known as the "Alma sector," where there were storms Saturday, Cook said.
The pilots would have had to "zigzag" to avoid the storms, adding more extra miles to their trip, Cook said.
The FAA said the flights were directed only 33-50 miles out of the way.
Besides rerouting the flights, the supervisor also ordered a veteran controller to leave the four flights "stacked" at varying altitudes above 30,000 feet rather than bringing them all down to 30,000 feet and stringing them out in a line, as would be the normal practice before reaching the Alma sector, Cook said. The supervisor told controllers he wanted to leave the planes stacked so the trainee could practice unstacking them.
The supervisor also ordered a veteran controller to tell one of the four pilots to report an incorrect altitude to see whether the trainee would catch the mistake, Cook said.
"To do this with live traffic, airliners that are full of passengers, well, it's reckless. It's beyond reckless," Cook said.
The FAA and the controllers union are at loggerheads over staffing of traffic control facilities. Union officials say many facilities are understaffed or manned by trainees without adequate experience. FAA officials say the union exaggerates in order to gain leverage in contract negotiations.
Delta spokeswoman Betsy Talton declined to comment on the incident. Southwest spokeswoman Brandy King said the airline wasn't aware of the incident. Virgin spokeswoman Emily Andariese said she was unaware of the incident.