FAA Report on Controller Errors : Stacking of Jets Cited as Problem at O’Hare

The practice of stacking the paths of flights in and out of Chicago’s O’Hare International Airport may have contributed to a steady increase in the number of mistakes made by air traffic controllers, according to a government review of O’Hare’s flight operations.

In a monthlong investigation of O’Hare, launched after controllers began making unusually high numbers of errors this year, the Federal Aviation Administration found that 150 flight paths were intersecting every day at a point 50 miles southeast of O’Hare.

The crossover of high-flying arrivals and low-flying departures, combined with additional traffic heading to and from nearby Midway Airport, may be too much for controllers to handle, the agency concluded.

That assessment and other problems at the nation’s busiest airport are described in an internal FAA report obtained by the Washington Post. The report was written last week as the FAA moved to reduce traffic into O’Hare to safeguard against further controller mistakes.

Routine Layering Practice

The intersection of flight paths around busy airports is a routine practice. Planes are assigned different altitudes so they cannot collide. In citing the location 50 miles southeast of O’Hare, the FAA report urged that some of the jet traffic be rerouted, to eliminate confusion that could lead to mistakes. The report suggested that departing flights at that point be limited to those bound for Washington and Baltimore, and that flights to Dayton and Columbus, Ohio, and Philadelphia should be sent out by another route.

The review of O’Hare, which covered everything from controller training to runway lighting, was not the first in recent years. The National Transportation Safety Board has conducted three studies of controllers there in two years, and the FAA probe is just one of several efforts by that agency.

The country’s largest hub airport is situated amid some of the most complex traffic patterns in the air traffic control system. Controllers in O’Hare’s radar room also direct 3,700 flights daily for up to 12 lesser airports in the Chicago area, including Midway, where traffic has increased 45% in the last decade.

Not Enough Controllers

O’Hare operations suffer from a chronic shortage of experienced controllers, and FAA efforts to attract and train apprentices have been hampered by factors ranging from the high cost of living in Chicago to the stressful working conditions.

The report noted that O’Hare’s controllers work in rundown and overcrowded facilities with equipment so antiquated that spare parts are not available. The tower that oversees O’Hare landings and takeoffs is so cramped that there is not enough room for trainees, and without that phase of training, an apprentice cannot advance to journeyman status.

In the underground radar room, the second busiest in the country, the equipment is so old that controllers at some stations use different versions of the same equipment, and that further complicates training.

Many of the recommendations to FAA Administrator T. Allan McArtor point out the obvious, such as the need to repair leaking roofs, walls and floors to improve controller morale, but the report also proposed more elaborate solutions. One calls for construction of a new, larger control tower. Another suggests that the airlines combine de-icing operations at de-icing pads located near the ends of runways.

Chaos of Construction

While the FAA’s facilities decayed, the rest of the airport has been under construction almost continuously, as the airlines build ultramodern terminals. The work has created chaos on the ground and contributes to the risk of a collision between taxiing jetliners.

“O’Hare has one of the most complex taxi systems of any airport in the country,” the report said. “Additional confusion can be attributed to extensive construction, resulting in almost daily relocation, opening and closing of various areas.”

The FAA noted that runways and taxiways are not clearly marked. Signs are inconsistent and bear complicated names instead of the alphabetic code used at other airports around the country. Lighting causes confusion and hinders the movement of jets on the ground. The FAA team urged that directional signs and lighting be simplified.

The FAA estimated that traffic at O’Hare is expected to increase 6% over the next 10 years. Traffic at Midway is expected to grow an additional 31% by the end of the century.

Because of these projections, the FAA investigation also sought ways to squeeze more efficiency out of O’Hare.

Efficiency Suggestions

For example, the report suggested not only revisions in air traffic patterns, as in the case of the 150 crossover flight paths, but ways to abbreviate controller-to-pilot radio communications on the ground at O’Hare.

The proposal to change the way O’Hare’s runways are used perhaps best illustrates the FAA’s efforts to get the most use out of the airport. Of nine possible runway configurations, seven runways intersect. FAA procedures at O’Hare do not permit simultaneous approaches to converging runways if the runways are wet. This practice is allowed at other airports, and the team suggested O’Hare should explore this option. But first, the team observed, “the term ‘wet’ would have to be defined.”