An air traffic controller listening to three conversations at once — including a personal phone call — may not have heard a critical pilot error before a deadly collision over the Hudson River last year, investigators found.
Evidence gathered by the National Transportation Safety Board shows the controller at Teterboro Airport in New Jersey who handled the small plane that collided with a tour helicopter was talking with a friend on his headset while monitoring radio transmissions by the plane's pilot and another controller over speakers.
The controller, Carlyle Turner, directed the plane's pilot, Steven Altman, to contact nearby Newark Liberty International Airport on radio frequency 127.85, according to transcripts and other evidence released Wednesday. At the same second, a Newark controller was telling Turner there was another aircraft in the path of the plane and asking that he alert Altman.
One second later, Altman read back a slightly different frequency: 127.871.
"The simultaneous transmissions ... interfered with each other," a summary report by investigators said.
During both radio messages, Turner was on a phone call to a friend in the Teterboro operations office.
When Turner tried to contact Altman in response to the Newark request, he received no reply. Other attempts by controllers to reach Altman moments before the crash were also unsuccessful. If Altman was using the wrong frequency, he would not have been able to hear controllers trying to warn him.
Transcripts show Turner assumed he couldn't reach Altman because of radio problems, saying the pilot was "lost in the hertz." Moments later, Altman's plane collided with a tour helicopter lifting off from the New York side of the river. Altman, his two passengers, the helicopter pilot and five Italian tourists on board the helicopter were killed.
The Aug. 8 accident is likely to be raised at an unusual public forum by the safety board next month on pilot and air traffic controller professionalism. After a series of incidents over the past year, the board is examining ways to prevent pilots and controllers from becoming distracted.
