The 10 loudest planes that flew into Dallas Love Field in March were not the commercial jetliners flown by American and Southwest airlines. They were cargo planes, business jets and sports team charters, according to the city's aviation department research obtained by The Dallas Morning News.
General aviation and cargo flights, with older engines and far fewer noise restrictions, make up about two-thirds of Love's total flights. That puts the noise debate - and the tussle over the Wright amendment - in a new light.
Wright amendment backers have made noise the central focus of their campaign, through television ads, direct mailings and door-to-door canvassing.
Any changes to the 26-year-old law that restricts long-haul flights from Love would bring more planes and more noise to neighborhoods, they contend.
"We just don't want Love Field to get any bigger and bring more large jets in there," said Jay Pritchard, executive director of Stop-and-Think, funded by American Airlines Inc. to get residents to oppose changes to the Wright amendment.
But pro-repeal forces say more commercial flights would actually make Love Field quieter by pushing out louder business jets and cargo planes - an assertion backed by the airport's staff. Theoretically, they say, the business jets would seek less congested airports so they wouldn't have to compete with commercial schedules.
"It's consistent with what we've thought all along, that the general aviation planes are to blame for most of the noise," said Anthony Page of Friends of Love Field, a pro-repeal group.
Stop-and-Think, which received $1 million from Fort Worth-based American, is set to hold a news conference today on noise.
According to the city's rankings, some of the planes flown by the group's sponsor are among the 20 loudest during takeoff.
"We realize our planes make noise, and that's in no way beneficial to the neighborhoods around Love," said American spokesman Tim Wagner.
If neighbors realize the trade-off of more noise resulting from more passenger flights at Love, they'll reconsider Southwest's campaign to repeal the Wright law, he said. "They're hearing it 100 times a day, and what would the impact be if it were 300 or 400 times a day?"
Southwest's 120 flights a day dominate Love's passenger side, while American is flying seven MD-80 flights a day split between St. Louis and Kansas City. American also flies quieter regional jets, as does Continental Airlines Inc., the third commercial passenger airline at Love.
Southwest's older planes, Boeing 737-300s, rank No. 11 in terms of approach noise. American's MD-80s come in at No. 22, by the same measure, but are louder than any Southwest aircraft on takeoff.
There are some caveats on the city's noisy-plane list. It measures only the takeoff sound of the engines measured by federal regulators at a distance of one-eighth of a mile from the end of a runway. And it measures approach noise only between 1,000 and 2,000 feet, though the measurement can vary slightly.
The city's list also doesn't account for Southwest's planes that have noise-reducing winglets, and it also may not reflect some modifications to engines.
Most important, it doesn't show how far the loud noise from some jets extends from the airport. According to Boeing Co. and Love Field's own noise research, American's jets have a noise footprint - the area where noise is heard - twice as large as newer Southwest planes. That means American planes are heard longer and farther from the airport.
The noise issue is overblown by people fronting for American, Southwest Airlines chairman Herb Kelleher said Tuesday.
"There are more households affected by noise from Dallas/Fort Worth International Airport than by any noise from Love," Mr. Kelleher said. "Why don't these people take it up with D/FW?"
The list of noisiest planes shows the real culprit isn't commercial planes, Mr. Page said.
Love Field staff said that it's possible that smaller general aviation fliers could leave if the airport gets more commercial passenger flights.
Dallas Mayor Laura Miller has also advocated moving some cargo and business jet activity from Love to Dallas Executive Airport, where the city just unveiled a new terminal and other improvements. Executive, in southwest Dallas, faces its share of noise critics as well.
Noise is a complicated issue because so many factors - including humidity, wind and temperature - change how planes sound from the ground.
And people's sensitivities vary.
A jet that flies late at night or during pre-dawn hours may be just as loud as one that flies at noon. But it also may be more annoying. Some Love cargo operators have to fly during pre-dawn hours; Southwest and American stop flying before midnight.
The Federal Aviation Administration considers 65 decibels to be the average noise level incompatible with homes and other development. At Love Field, that's a fairly limited area of 2 square miles - most of which is on airport property.
Southwest's Mr. Kelleher said his airline's flying creates 65 decibels only to Mockingbird Lane. "We are not the problem here," he said.
Peter Kirsch, a Denver-based attorney who represented Grapevine, Euless and Irving in their fight against D/FW Airport in the late 1980s, said the 65-decibel threshold is merely a planning guideline and doesn't reflect how much airport noise exists.
The guideline is an annual average, created by taking measurements throughout the day, under a variety of weather conditions.
"If you put one hand in ice water and one in a flame, you'd technically be at room temperature, but that doesn't reflect the situation," Mr. Kirsch said. "It could mean sometimes there are noise events at 105 decibels, and sometimes there's no noise at all."
Noise levels improving
During the last two decades, the number of people affected by average noise levels above the 65-decibel level dropped to 1 million from 10 million.
"But noise is relative, and as the environment improves, people's expectations increase," he said.
Love Field had one of the nation's earliest noise programs, an effort that marked the birth of the Love Field Citizens Action Committee. The airport has 13 noise monitors and uses them to track airplanes or helicopters that stray from the established - and least intrusive - procedures.
The airport is quieter than it was before 2001 because commercial passenger activity remains down, meaning fewer large jets.
Pat White, co-chair of the Love Field Citizens Action Committee, said noise contour maps don't tell the whole story.
While her home in Bluffview is outside even the 55-decibel zone calculated in 2000 as part of the Love Field Master Plan, "that doesn't mean we don't have impact."
"It's not like it's quiet once you cross over the line," she said.
And while the Master Plan's projections for noise in 2010 show the noise footprint shrinking, that assumes a fleet mix of mostly regional jets, which are much quieter than mainline jets used by Southwest and American.
"If they open up Love Field, the 65[-decibel] area is going to creep much further out, and we can't do anything about it," Ms. White said. "We don't want to move backwards, and that's what would happen."
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