A Simulating Experience

Between August and September 2005, controllers from O’Hare fast-forwarded to the year 2018, operating a real-time, human-in-the-loop simulation of a new airport layout plan defined by the O’Hare Modernization Program.


Nine controllers from the O’Hare tower participated in the simulation. Since this was a substantially new airport, they underwent their own training to prepare for the simulation. A two-day class was conducted at O’Hare in May 2005 in which the controllers were briefed on the new airport layout, runway and taxiway names, and the proposed traffic flows. In addition, each of the controllers spent at least five days at FFC, controlling traffic during sim-pilot training.

The simulation itself was conducted over a five-day period in September 2005. There were four runs per day, each lasting 45 minutes. Controllers were exposed to East and West traffic flows, in both visual and instrument conditions, with traffic levels that approached 300 operations per hour. Some runs introduced traffic management initiatives to create more complicated — and more realistic — traffic situations. In addition, gate-holds for occupied gates were required; go-arounds were issued when appropriate; and one run simulated an aircraft breakdown on arrival; and the subsequent runway closure. All of these factors provided the controllers with a very real sense of how the airport will operate when it’s completed.

The controllers staffed the FFC tower for each simulation run as follows: a total of six local/ground controller positions, one outbound ground-metering position, one inbound-metering position, who managed the arrival flight strips, and one traffic manager. Controllers changed positions for each run to expose them to all of the positions in the tower.

Data Collected

The main focus of the data-collection effort was on data not readily available from the fast-time analysis. Digital audio recordings of pilot/controller communications were generated for each run, and processed to provide statistics such as number of transmissions per hour, and average length of transmission. These data are useful for workload analysis and are a factor in the safe operation of the airport. During each run, activity in the control tower was recorded on video to document such factors as controller coordination, and the physical workload of each position — how much moving around in the tower was required, and the scope of their respective viewing ranges.

At the end of each run, the controllers filled out surveys. The surveys asked controllers to rate various factors for the new ALP relative to their current experience at O’Hare, including traffic complexity, aircraft ownership recognition, tower coordination, and radio communication. Also, debrief sessions were conducted after each run in which the controllers provided feedback from the run.

This feedback ranged from the positives and negatives for the run, to what changes could be made to improve their ability to move the aircraft. These suggestions included ideas on how to better balance the workload in the tower and move the aircraft more efficiently, and how the airport layout might be altered to address particular problems encountered in the traffic flow on the airport surface. Some of these ideas were implemented in subsequent simulation runs to test their effectiveness.

What WAS Learned

“NASA’s facility helped us determine how our air traffic operation can work at peak efficiency within the tower at the future O’Hare,” according to Suzan Jardine, Project Lead for Central Terminal Operations in the Chicago Area Modernization Program Office. “The simulation offered a unique opportunity to study how FAA air traffic controllers can best communicate with each other and interface with the tower’s new technology and new demands. As O’Hare Airport modernizes, the FAA will be able to hit the ground running and keep the air traffic operation performing smoothly.”

The O’Hare simulation provided a unique opportunity for stakeholders to experience the proposed ALP. During their time in FFC, the controllers were able to make significant improvements in several areas, including workload balancing and chokepoint mitigation. There were also suggestions regarding the airport layout that might improve the efficiency of the operation. The findings from the simulation provided the OMP office a basis to open a dialog regarding future modifications to the ALP that would enhance overall operations.

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