An air traffic controller distracted by a "nonpertinent" phone call while on duty was the main factor causing an August 2009 midair above the Hudson River in New York, the NTSB said on Tuesday. All nine people on board a Piper Lance and a tour helicopter were killed. The board also faulted the FAA's see-and-avoid rules in the Hudson corridor. It was not possible for the helicopter pilot to see the Lance approaching from behind, the board said, and investigators showed that it would have been difficult for the Lance pilot to see the helicopter against the city skyline until it was too late to react. The controller failed to notice when the Lance pilot read back the wrong frequency, and as a result, controllers were unable to reach the pilot in time to warn about the conflict.
The Teterboro ATC facility was adequately staffed, the NTSB said, and controllers were working one hour on and one hour off. The local controller initiated two personal phone calls while handling traffic. A manager on duty was aware of the first call but "did not address the issue as required," the board said. Also, both pilots had traffic advisory systems in their cockpits, but apparently overlooked or ignored conflict alerts. The FAA said on Tuesday it took "swift action" after the accident to enhance the safety of the air corridor. New FAA rules now in force for the Hudson River define separate corridors for aircraft flying locally and those in transit.