The National Transportation Safety Board said in a report that the controller, who has not been identified, cleared the single-engine Piper for takeoff at 11:48 and 30 seconds a.m. EDT, then made a telephone call. He remained on the phone, including while further instructing the plane's pilot, until the accident happened.
The phone call, to an airport contractor, was a "silly conversation" concerning a dead cat that had been removed from the airport, a retired union official said, in an account supported by transportation officials also familiar with the contents of the call.
After takeoff, the plane flew southbound until the controller directed it to turn left toward the river, the report said. At 11:52 and 20 seconds, the controller instructed the plane to contact air traffic control at nearby Newark Liberty International Airport, which is part of the procedure for handing off oversight of the small plane.
The pilot apparently did not contact Newark, the report said. Radar data show there were several aircraft immediately ahead of the plane, including the tour helicopter, "all of which were potential traffic conflicts for the airplane," but the Teterboro controller didn't warn the pilot, the report said.
It wasn't until controllers at the Newark airport alerted the Teterboro controller to the potential collision that he twice tried unsuccessfully to contact the pilot, the report said. The collision occurred at 11:53 and 14 seconds.
At the time the Newark controllers were alerting the Teterboro controller to the danger, they also recommended the plane turn southwest. The plane's pilot apparently overhead that and acknowledged the instruction, the report said.
Video of the crash taken by a tourist sightseeing near the Statute of Liberty show the Piper changing direction seconds before its wing was clipped by the helicopter's rotors. The plane then broke apart in the air and both aircraft plunged into the Hudson.
Union officials representing air traffic controllers said the Teterboro controller couldn't have warned the Piper pilot of the helicopter in its path at the time the plane was directed toward the river. They said the helicopter was just taking off and hadn't appeared on the radar screen yet.
"He was out of communication with the guy by the time the helicopter ever popped up on anybody's radar scope," said Phil Barbarello, National Air Traffic Controllers Association eastern region vice president.
The FAA has said there is no reason to believe the controller's actions contributed to the accident. However, the agency said the phone conversation was inappropriate and such conduct is unacceptable. The safety board, in a pointed statement, said it was too early to reach any conclusions about controllers in the crash.
The supervisor's conduct also is being investigated because he was out of the building at the time. Controllers, including supervisors, are expected to be available throughout their work shift in case they are needed, even if they are taking a break.
The NTSB report said two other Teterboro controllers were taking a break at the time of the accident. The only controllers on duty were the controller who was talking on the phone and another controller who was handling arriving planes and ground traffic.
The phone call, made on a landline that controllers use to contact other parts of the airport, was to an employee of Baltimore-based AvPORTS, a contractor for the Port Authority of New York and New Jersey, which manages the airport, according to port authority officials.
"He was talking to the Port Authority about a dead cat on the taxiway ... it turned into a silly conversation," said Barrett Byrnes, a recently retired air traffic controller and former National Air Traffic Controllers Association representative who stays in touch with New York and New Jersey controllers. "There was a little banter."
Three officials close to the investigation verified that the banter was about a cat carcass on the airport grounds.
A federal task force began work Friday on improving safety procedures for pilots flying in the busy airspace around New York City and was given 10 days to report, the FAA said.
Caruso reported from New York.