With the New York City skyline as a backdrop, a United plane prepares to land at Newark Liberty International Airport in Newark, N.J.

(AP Photo/Julio Cortez)

WASHINGTON — A safety program that encourages air traffic controllers to voluntarily disclose their mistakes in exchange for amnesty from punishment needs significant improvement before it can work effectively, according to a report released Monday.

The program has been FAA's primary answer to the problem of controller errors that bring planes dangerously close together. It encourages greater reporting of mistakes by promising not to punish controllers who disclose errors within 24 hours of an incident as long as the errors aren't the result of gross negligence. The idea is to use the data gathered to better spot safety trends and take corrective action.

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The program — which FAA began to phase-in in 2008 — had collected more than 41,000 reports as of the end of last year, showing "promise as a tool to promote increased safety reporting," the report by the Transportation Department's inspector general said.

But the FAA has only recently developed processes to analyze the data that has been amassed, the report said. Also, due to program rules designed to protect the confidentiality of controllers who file reports, much of the data collected isn't verified for accuracy, the report said.

And, the agency hasn't fully developed a process to effectively share the data that's been collected with individual air traffic control facilities around the country so that local improvements can be made, the report said.

The FAA "will need to make significant improvements" before the program "will be able to effectively identify and address the root causes of safety risks," the report said.

In one case cited by the inspector general, the program accepted a report from a controller who was watching a movie while on duty, protecting the controller from punishment.

"We consider this a conduct issue that requires management attention rather than a safety issue appropriate for a confidential safety program," the report said.