December 19, 2000 Chicago Tribune


By Jon Hilkevitch and Rogers Worthington, Tribune Staff Writers. Staff writer Rogers Worthington reported from Chicago.
December 19, 2000

DENVER -- Under perfect conditions, United Airlines senior pilot Tom Graff can take off on a flight path that keeps the plane over non-residential areas, minimizing the impact of engine noise that rattles windows and frays the nerves of residents living around O'Hare International Airport.

Rarely do those conditions exist. Powerful wind gusts and other weather problems usually force pilots to stray from the course and from complying with a program for nighttime flights intended to mute noise complaints in the neighborhoods around O'Hare.

But Graff is among those hopeful an experiment under way at a United testing facility here will help airlines abide by Chicago's "Fly Quiet" program and reduce the tensions between the city and suburbs over operation of O'Hare.

Instead of a pilot guiding the plane during takeoff using compass headings--the customary practice that usually results in planes straying over heavily populated areas--the experiment allows a computer onboard each aircraft to take over navigation.

"By automating the takeoff procedure and putting planes exactly where you want them, we are home free with the noise problem," Graff said. "Nobody will deviate from the preferred course. ... Nobody will turn early and spill noise into someone's back-yard barbecue party."

At the proving ground in Denver, Graff and other pilots are using flight simulators to test the effectiveness of the master computer called the Flight Management System, or FMS.

On Tuesday, city aviation officials plan to brief the O'Hare Noise Compatibility Commission, a panel of officials from Chicago and the suburbs around O'Hare to deal with airport noise issues, about the recent trials.

Although the Federal Aviation Administration still must sign off on the project, aviation officials are hopeful pilots flying out of O'Hare can begin using the computer navigation system by next summer.

At the United flight center, the simulator recreates conditions faced by pilots almost daily. During a recent session, Graff sat in the cockpit while winds buffeted the left side of the jet to blow it off a track designed to take the plane over the Tri-State Tollway.

Normally that might take the plane a half-mile or more off course, over hundreds of houses in Elmhurst.

But when the FMS was engaged, hundreds of minute adjustments were made to the plane's flight path and deviation from the desired track was virtually wiped out.

The experiment involves programming a set of "way points" into the database of each aircraft's computer to handle the takeoffs.

The way points are a series of longitude, latitude and altitude positions in space that define departure routes for late-night and early morning flights out of O'Hare. Once the computer receives signals from ground navigation stations informing it of the aircraft's position, the computer relates the data to the way points. Then it tells the plane where it needs to be next.

Rocky Stone, manager of United flight systems, said flights that sometimes drift as far as 2 miles off track can be kept within 600 feet of the preferred route using FMS.

FAA officials are expressing interest in the noise-abatement testing, but they said it is premature to pass judgment on the project, which will require the agency to re-examine flight-operations procedures and the use of the airspace in the Chicago area.

"Some of our air-traffic folks have received briefings on what United and the city plan to do, but it's too early in the process for us to offer constructive feedback," said FAA spokesman Tony Molinaro.

Chicago's recommended "Fly Quiet" routes, which take planes over forest preserves, highways and industrial parks, have been in the hands of every airline operating at O'Hare since 1997. But adherence to the voluntary tracks has been inconsistent, angering suburban mayors who bought into the program as a partial remedy for noise, and confirming the suspicions of activists opposing O'Hare expansion.

"The tolerance for these quality-of-life interruptions has reached its maximum," said Arlington Heights Mayor Arlene Mulder, chairwoman of the Noise Compatibility Commission.

But with air traffic growing, and with it the need for additional facilities, airlines have been trying to mend relations with communities around major airports that have traditionally opposed expansions.

In 1999, there were an average of 288 flights daily during the voluntary Fly Quiet hours of 10 p.m. to 7 a.m., according to the Chicago Department of Aviation.

Many noise-weary neighbors of O'Hare say neither the more than $130 million that Chicago has spent on soundproofing houses and schools nor the reduction in aircraft noise in the last three years due to the phase-out of older, noisier aircraft has gone far enough to make a difference.

The preliminary simulator results--using Airbus A320, Boeing 737 and 777 aircraft on different runways at O'Hare--have been encouraging, said Chris Arman, an assistant aviation official with the city.

During the simulation tests over the last two months in which the FMS computer did the flying, the aircraft consistently stayed over the desired, nonresidential track, according to data from testing.

"We in the airline industry don't often get a chance to be pro-active in our dealings with people living in the most noise-sensitive areas around airports, which is a 5-mile radius after takeoff," said Stone, a 737 captain. "This is an opportunity to provide immediate relief. I don't see why the program cannot be approved and implemented by next spring."

During tests, FMS-aided departures followed the intended course away from residential areas, even when conditions such as windshear and 115-degree temperatures were programmed into various situations.

The FMS, which on a Boeing 747 directs and monitors the actions of up to 200 smaller computers, for years has been used to fly aircraft when the autopilot is engaged, to land the plane by itself in zero visibility and to perform many other flight functions.

A map of the actual takeoff paths followed this year show numerous errant lines as planes routinely drifted over residential areas.

Officials at the Chicago Department of Aviation and United said they hope the FAA certifies the plan by summer. The plan also must get the support of air-traffic controller and pilot unions. Both will be asked to join a task force on the project.

Some controllers are concerned that not all aircraft have the technology. About 80 percent of commercial planes in the U.S. fleet have FMS, according to the Air Transport Association, which represents the major airlines and cargo carriers.