NEW YORK » It is known as the Flushing Climb – an airplane route born 23 years ago to prevent planes taking off at La Guardia Airport from disturbing fans at Arthur Ashe Stadium during the U.S. Open.

But the Federal Aviation Administration, as part of an effort to deal with congested airspace, has quietly approved for much more frequent use a version of the route in which planes, rather than fanning out, fly a narrower, more precise path. This has infuriated residents of Queens living underneath, who contend that they had no say in the change and that the noise has become unbearable.

The FAA, however, concluded that the noise effect of the narrower route, christened the Tennis Climb, was permissible, even though the agency conducted a six-month test run last year – without telling the public – that yielded a flood of complaints.

Part of the problem in determining who is right is that unlike in other cities, there are not enough noise monitors in New York City to accurately track the cumulative effect of the noise, some elected officials said.

For many officials, activists and New Yorkers, the FAA’s move was yet another example of what they see as the agency overriding community anguish in pursuit of its own ends. They fear that airplane noise will worsen as more planes fill the skies, and that the public will have little recourse.

The Tennis Climb from La Guardia is now used throughout the year to allow greater use of certain runways at Kennedy Airport. Unlike earlier departure routes that fanned outward and headed east, then north, its path looks as slim as a feather. The route was tailored for planes equipped with new GPS-based precision navigation.

But hewing to a narrower line often means that the same houses are flown over again and again.

"It’s like having screaming jet engines right over your house," said Janet McEneaney, who has lived in Queens for 15 years, and last year founded a group called Queens Quiet Skies. "You can’t even have a conversation in your own living room. You can’t hear the television. You can’t talk on the phone." The planes might start at 6 a.m., she said, and stop at 2 a.m.

More airlines are expected to embrace precision navigation to reduce fuel consumption and emissions. The FAA and the airlines say it will actually reduce the problem of noise because fewer people will be affected. And when planes use precision navigation to descend, they say, the aircrafts can almost glide in rather than keeping their engines powered up, resulting in lower emissions and less noise.

"Geographically, the aircraft will always be over the same spot every day – the same house," said Joe Devito, manager of flight standards compliance at JetBlue, whose entire fleet is equipped with the technology. But "under the old procedures, I’d come in with engines powered up," he said. "Today I’m going over the house with the engines on idle. That’s nice and quiet."

But some wonder whether the airlines and the FAA have underestimated, or understated, the noise effect, especially in the case of the Tennis Climb.

Under terms of the 2012 act funding the FAA, precision navigation can be exempt from extensive environmental studies if it is deemed to have no significant environmental impact, or to reduce fuel consumption, emissions and noise on a per-flight basis. But gauging the noise has proved difficult.

A recent report found that the FAA did not have the technology to track the noise of each flight. There are also disagreements over what constitutes "significant" impact. While the FAA concluded that noise generated by the Tennis Climb was not significant, Queens residents heartily disagree.

"People are saying it’s 10 times louder than it was ever," said state Sen. Tony Avella, D-Queens. He and other elected officials are pushing the agency to conduct a more thorough environmental review.

The adoption of precision navigation coincides with another FAA effort: redesigning the nation’s airspace to improve efficiency and reduce delays. The FAA said the projects are not related.

But in its analysis of the airspace redesign, the Government Accountability Office noted that the agency failed to account for how loud precision navigation might be for some residents, saying the technology "may have resulted in fewer people impacted by noise but to a greater degree."

Indeed, New Yorkers who have long battled airplane noise fear that precision navigation will worsen the problem. And some in communities including Park Slope and Bedford-Stuyvesant, both in Brooklyn, say they have already been subjected to far noisier skies in recent years, with planes seemingly flying lower, and with increased frequency.

However, officials say they have not introduced any new precision navigation routes over those neighborhoods – though planes equipped with that technology can use pre-existing routes – and that flight altitudes have not changed.

"The only thing that has changed are the wind and weather patterns, which determine the runways we use, so we are using arrival routes over Brooklyn slightly more often than in previous years," Laura Brown, an FAA spokeswoman, said.

Kendall Lampkin, the executive director of a Nassau County coalition that has pushed for quieter airspace around Kennedy Airport for more than 40 years, said that while noise had seemed to worsen over communities there, it remained a "back-burner" issue for both the FAA and the Port Authority of New York and New Jersey, which operates the region’s biggest airports.

While the FAA uses computer modeling to gauge noise effect, as allowed by law, activists and elected officials say readings from noise monitors are needed. Yet La Guardia and Kennedy have just 15 noise monitors between them, compared with 33 at O’Hare Airport in Chicago and 30 in metropolitan Boston. The Port Authority is upgrading its noise monitoring system and is considering adding monitors, a spokesman said.

There are limits on airplane noise; the federal government uses a measure called a day-night average sound level, which averages airplane noise exposure over a year. A spokesman for the Port Authority said that thanks to quieter plane engines, few pockets of the city match or exceed the allowable limit of 65 decibels, and those that do are quickly shrinking. Together with the FAA, the authority has soundproofed 77 schools, with its share of the cost being $360 million.

A bill recently passed in the New York Legislature would require the Port Authority to conduct a sweeping study of the cumulative noise levels and land use compatibility around the city’s airports. That study, which dozens of other airports have undertaken, could result in planes’ being rerouted and open the door to federal financing for soundproofing homes. The bill awaits Gov. Andrew M. Cuomo’s signature. For the study to go ahead, a similar bill would have to pass the New Jersey Legislature and be signed by Gov. Chris Christie.

For years, the Port Authority has resisted executing the study, saying its noise monitoring and soundproofing efforts were sufficient. Plus, said Chris Valens, an authority spokesman, "there is simply not enough funding in the Port Authority or FAA budgets to soundproof private homes and businesses."

Compared with standards set in Europe and other federal agencies, the FAA’s measure for gauging how loud is too loud is unusually lenient. Other federal bodies and councils, including the Department of Housing and Urban Development, the Environmental Protection Agency and the National Research Council, recommend a day-night measure of 55 decibels.

Henry Young, an aviation consultant, said the day-night measure of 65 decibels was created when the prime concern about noise was hearing loss. But nowadays, there is a wider realization of other ill effects, including high blood pressure and stress.

Young, who strongly backs the noise study, said the maximum allowable level should be 55 decibels.

"In the end, people sleep, students get better grades, houses are worth more money," he said. "Nothing but good stuff is going to come out of this program."

© 2013 The New York Times Company