Sunday, December 28, 2014

Answers to chronic flight delays may be buried in the numbers

Efforts to restore what's conspicuously absent in the airline industry — consistently reliable service — are getting a boost from the work of University of Michigan researchers who are looking closely at 73 million flights during the past decade.

It's no small task, but the key to running a smoother airline operation with fewer delays and cancellations during bad weather is buried in voluminous amounts of historical flight data, in fact more data than the airlines have the time and capacity to analyze, the researchers say.

Behind the scenes, it takes thousands of people to help operate a major airline, and it's a safe bet that many of those who are on duty at this very moment probably have their hands full trying to prevent small problems from boiling over at major hub airports and cascading across the country at several hundred smaller airports.

It is the nature of the business, an aspect that is virtually invisible to the traveling public. Snap decisions must be made on issues running the gamut, from cancellations to catering, to selecting which plane among a queue of aircraft that landed within minutes of each other will be assigned to the next available gate at the terminal.

Often, the solutions are imperfect, based on the calculus of ruining the day for the fewest number of passengers scheduled to connect to other flights during the next hour when a bank of 50 planes will taxi to departure runways.

Surely there is no time, and no apparent benefit from the standpoint of airline flight dispatchers, ramp managers and an assortment of other key personnel toworry about next week or fret about what could have gone more smoothly last week.

But the tendency toward tunnel vision instead of prioritizing the larger picture might also point to precisely whythe commercial aviation industry sometimes appears to passengers to be caught flat-footed, particularly when bad weather suddenly flares in any or many of the time zones in which the air service operates.

The Michigan researchers are crunching publicly available data from 2003 through 2013, covering all of the 73.8 million scheduled commercial flights in the U.S. as well as about 47 million hour-by-hour weather reports spanning each 24-hour period over the 11 years, said Brian Lemay, a doctoral student who is leading the project. The flight data being scrutinized is routinely collected and stored by the U.S. Department of Transportation, and the weather information is reported by the National Oceanic and Atmospheric Administration.

The research project is using advanced data analytics, drilling down to details as small as taxi time and wind direction to identify patterns that the airlines perhaps haven't detected, the Michigan professors and graduate students said.

"We have the time and the luxury and the resources to look at this one and two and three levels deeper'' than the airlines, said Amy Cohn, an associate professor in industrial and operations engineering at Michigan who researches airline industry operations.

The research team doesn't expect to come up with "the one key piece of information that somehow no one at the airlines ever saw and that is going to radicalize the industry," Cohn said. "I think it is more a function of having, frankly, a bunch of really smart kids who are digging into the data."

"The benefit of the work we are doing is going to be in the nuance, to help the airlines make some decisions in a more customized way,'' she said. "We expect the findings will lead us to suggest that at this time of day, in this part of the country, at this time of year, under these conditions, this is what you need to better allocate resources and have reliability."

Cohn said data collected during the project may be used to build computer-modeling software that could predict the outcome of an infinite number of hypothetical flight and weather scenarios, helping airlines spot likely weather delays in advance and to adjust their schedules and staffing levels to minimize disruptions.

Initial information is expected to be available over the next three to six months. It will be published in academic journals and also shared with the airlines and the Federal Aviation Administration, the research team said.

The No. 1 goal is to shine a light that enables airlines to predict and mitigate weather-related flight delays before they spiral from airport to airport, she said.

"What we are trying to do is to give a better sense of saying if it is storming in Chicago at 4 p.m., what do we think will be happening in Detroit at 5, 6 or 7 p.m.?'' Cohn said. "And where else should you be looking — in California at noon, in Dallas at 11 a.m. — to obtain the best predictive value?"

"We are trying to better understand what these patterns look like and the relationships between airline operations, tactical decision-making and weather, and how delays beget other delays (at airports) downstream," Cohn said.

She acknowledged the airlines have improved their capabilities in the last few years, particularly during winter, when approaching snowstorms can be forecast days in advance. Summer, with pop-up thunderstorms, presents a different challenge.

"But if you have a better feel for where the downstream effect is going to be four and six hours from now, then you might be able to bring in extra resources like reserve crews,'' she said. "Six hours is enough time to begin re-accommodating connecting passengers onto other flights, through Dallas, for example, because Chicago is in jeopardy due to storms."

Officials at United Airlines and American Airlines, both of which operate hubs at O'Hare International Airport, said to some extent they already carry out similar analysis internally to make their operations more efficient. But they said more information is welcome.

"We have professionals in our integrated operations center — operations people and meteorologists — who analyze the weather, study historical data and work together to make the best decisions for our customers,'' American spokeswoman Leslie Scott said.

"We are proactive about that analysis and making those decisions when we can be — for example, before the Thanksgiving week storm in the northeast and the projected Christmas Eve storm here in Chicago. In both of those instances we proactively canceled flights and issued flexible travel policies.

"That said, we're always looking at new ways to improve our operation and better serve our customers," Scott said.

United officials said improved technology has helped airlines to become more proactive in responding earlier to bad weather and "any additional information can be helpful with that process."

The FAA did not answer questions submitted by the Tribune.

- Original article can be found at:

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