WASHINGTON — The Federal Aviation Administration is proposing to keep secret from travelers its vast records on how frequently and where commercial planes are damaged by hitting flying birds.

The government agency argued that some carriers and airports would stop reporting the incidents for fear the public would misinterpret the data and hold it against them. The reporting is voluntary because the FAA has refused a decade-old recommendation from the National Transportation Safety Board to make it mandatory.

The agency’s formal secrecy proposal came just after FAA officials had said they were going to release the huge database to The Associated Press in response to a Freedom of Information Act request.

As President Barack Obama promises a more open government, the FAA says it needs to expand secrecy to cover this safety data because if the public learned the information, then airports and air carriers wouldn’t report damage from birds.

“To have the government actually chill public access to safety information is a step backward,” said James Hall, former chairman of the National Transportation Safety Board. “Public awareness is an essential part of any strong safety program.”

After a multiple bird strike forced a US Airways jet to ditch in the Hudson River on Jan. 15, the AP requested access to the bird strike database, which contains more than 100,000 reports of bird strikes that have been voluntarily submitted since 1990.

In a Feb. 18 conference call, FAA officials promised the AP the agency would turn over the data within days. Since then, the FAA has said only that the AP’s request for the data under the Freedom of Information Act was “under review.”

Last Thursday, the FAA quietly published its proposal to keep the data secret in the Federal Register, the government’s daily compendium of new and proposed rules and regulations in their dense legal language.

The agency’s proposal rested on the assumption that some carriers and airports it regulates would allow concerns about their image and profits to override efforts to keep passengers safe.

“The agency is concerned that there is a serious potential that information related to bird strikes will not be submitted because of fear that the disclosure of raw data could unfairly cast unfounded aspersions on the submitter,” the FAA said in the Federal Register.

The FAA is particularly worried that the public will compare the data on various airports. “Drawing comparisons between airports is difficult because of the unevenness of reporting,” it said. Not only do some airports do a better job than others of reporting strikes, they also face different challenges based on the bird habitats in their areas, the agency said.

“Inaccurate portrayals of airports and airlines could have a negative impact on their participation in reporting bird strikes,” FAA added.

“It sounds like the FAA is going back to their early 1990s view that their job is to promote the carriers and look out for their bottom line,” said Mary Schiavo, former Transportation Department inspector general. “They were criticized for that and then said they also were concerned with safety, but this sounds like they’re reverting to being cheerleaders for the industry.”

“In this case, secrecy is going to kill,” added Schiavo, a pilot herself. She said that since the US Airways incident, businessmen have told her of corporate jets damaged in bird strikes and their interest in researching the problem, which she said the FAA’s proposal would hamper.

The FAA has rejected another method of dealing with the problem of unequal reporting by airports and airlines.

In 1999, the National Transportation Safety Board concluded that the voluntary reporting system fails to produce reports on many bird strikes so the FAA database “grossly underestimates the magnitude of the problem.” Further, the board quoted Agriculture Department experts as saying “over 50 percent of the reports lack the most critical piece of information about a strike, the species of bird.”

As a result, the board recommended that the FAA require that bird strikes be reported. But the FAA refused.

Meantime, the FAA acknowledges that, with increases in air travel and in the populations of dangerous large birds like Canada geese, the problem is growing. It said the annual number of strikes reported has grown from 1,759 in 1990 to 7,666 in 2007.

The FAA said in the notice that its wildlife strike database is “unparalleled.”

On Wednesday, after last week’s FAA proposal to keep the data secret, Melanie Yohe of the FAA told the AP the release of the database was “way overdue” and that “it should be with you right now.” She said there is “no reason for it to take this long.”

FAA officials have emphasized that the loss of both of a jetliner’s engines to bird strikes is very rare. The FAA’s engine safety rules do not require that engines continue to produce thrust after a bird strike, only that they do not break into pieces upon impact with a bird weighing eight pounds or less. Two years ago, the Bird Strike Committee USA, a voluntary group of government officials and industry executives concerned about the issue, sought additional action.

Richard A. Dolbeer, then committee chairman, wrote the safety board about four incidents in 2005-2007 in which both engines of an airliner were damaged — by yellow-legged gulls in Rome, canvasback ducks in Chicago, starlings in Washington, D.C., and doves in Ohio. In a 2005 incident, a Falcon 20 freight aircraft ingested mourning doves into both engines, lost all power, slid through an airport security fence in Ohio and across a highway into a corn field.

Noting that the incidents “occurred in widely diverse geographic locations and involved four different species of birds,” Dolbeer wrote that they “show the margins between safety and catastrophe are becoming rather thin.”