The National Air Traffic Controllers Association calls suggestions that an air traffic controller may have had anything to do with the midair collision over the Hudson River off New York City last weekend "absurd" and "insulting."
Two air traffic control employees were placed on administrative leave by the FAA after investigators discovered that the controller handling the single engine plane was on the phone when the accident took place.
"We learned that the controller handling the Piper flight was involved in apparently inappropriate conversations on the telephone at the time of the accident," the FAA said in a prepared statement Thursday night. "We also learned that the supervisor was not present in the building as required."
The FAA says they have no reason to believe the controller had anything to do with the accident, and said the unidentified controller had already handed off control of the plane to Newark airport when the accident happened.
But that did little to calm union officials.
"For the FAA to sit there and allude or make accusations that the controller had anything to do with this accident is absolutely absurd and very insulting," said Barrett Burns, from the National Air Traffic Controllers Association.
ABC News aviation consultant John Nance said on "Good Morning America" that the FAA has the "right and responsibility to discipline their people," but said that "it is as if they were trying to find somebody to blame."
The small Piper plane collided with a tour helicopter over the river between New York and New Jersey in an area not under the direction of air traffic controllers. However, air traffic controllers were in contact with the plane before the collision that killed all three people on the plane and all six aboard the helicopter.
The New York Daily News reported the "inappropriate conversations" were by a controller at Teterboro Airport, where the plane took off, who was on the phone with his girlfriend as he guided the plane toward the Hudson corridor on another channel.
The controller had cleared the single engine plane for takeoff before making the call, and was still on the phone when he handed off control of the plane to nearby Newark airport, which monitors low flying traffic on the Hudson.
New Video of Plane, Helicopter Crash Over the Hudson
National Transportation Safety Board and FAA investigators learned of the telephone conversation earlier this week while examining recordings of telephone calls on a landline phone in the tower that controllers use to communicate with other parts of the Teterboro Airport. The controller and supervisor were removed from duty immediately and the FAA has begun disciplinary proceedings.
Neither the controller nor his supervisor were identified by the FAA.
Air traffic controllers are expected to be alert at all times and are given frequent breaks, at least 15 minutes every two hours. The FAA said in its statement that while they have no reason to believe that the actions of the employees contributed to the accident, "this kind of conduct is unacceptable."
The plane was found Monday, 60 feet underwater, and raised later. The helicopter was recovered in 30 feet of water Sunday. Wreckage from the crash will be transported to Delaware today for further investigation.
The news of the disciplinary action against the controllers came as new amateur video emerged showing the collision between the helicopter and the plane. Investigators had been searching for such footage to aid in their investigation of the accident.
Nance said that the video, taken by a tourist on a boat in the Hudson, shows "two pilots that simply couldn't see each other" because of blind spots.
"Neither of them had any idea the other was there," he said. "It's very, very seldom in aviation safety that we have such graphic representation of what happened."
In the wake of the accident, critics are calling for more restrictions for flights within the crowded Hudson River corridor.
Questions Linger in Hudson Crash
In that area over the river, aircraft flying below 1,100 feet are virtually on their own, with no air traffic controllers guiding them in the crowded airspace. National Transportation Safety Board chairwoman Deborah Hersman said it's the responsibility of pilots "to see and be seen and be aware of traffic around them."
It's also a busy space: The area saw 225 flights every day in the week prior to the accident, investigators said.
"It is unconscionable that the FAA permits unregulated flights in a crowded airspace in a major metropolitan area," said Rep. Jerrold Nadler, D-N.Y., who serves on the House Transportation and Infrastructure Committee. "And it is ridiculous that private planes and helicopters flying through a crowded area are dependent, while in flight, on visually sighting other aircraft and communicating with them. The real-life repercussions of these non-existent regulations have been disastrous."
The "'see and avoid' concept is really bankrupt," Nance said. "Something needs to be done."
ABC News' Lisa Stark and Kate Barrett contributed to this report.