Air-traffic controllers in the New York area slept on the job, watched movies on duty, left work early and repeatedly violated safety rules, a U.S. investigative agency told the White House and Congress.

Controllers at the facility that monitors traffic in a radius of about 80 kilometers around New York also used careless and casual languages in communications with pilots, leading to at least one serious incident when planes got too close, the U.S. Office of Special Counsel, which investigates whistle-blower complaints, said in a letter today.

A separate complaint investigated by Special Counsel Carolyn Lerner charged that planes departing Teterboro Airport in New Jersey routinely got too close to jets flying to Newark Liberty International Airport, according to the letter.

The letter alleged that Delta Air Lines Inc. over several years didn’t comply with U.S. maintenance and safety requirements for fuel tank and wiring systems.

The allegations from those and other whistle-blowers at the Federal Aviation Administration were substantiated by investigators at the counsel’s office and the Department of Transportation, according to the letter.

“Given the recurring and serious nature of these concerns, I write with a strong recommendation that more rigorous oversight measures be put in place at DOT and FAA to ensure a higher standard for aviation safety,” Lerner said in the letter.

Supervisors Replaced

In the New York air-traffic facility, supervisors were replaced and disciplinary action was taken against three managers in 2011, according to the letter.

Spokesmen for DOT and FAA didn’t immediately respond to requests for comment.