Airline Dispatchers Research Articles

Use of Trajectory Option Sets to Support Collaborative Constraint Propagation

Air traffic flow management is supported by a highly distributed work system in which airline dispatchers and Federal Aviation Administration (FAA) traffic managers must coordinate. To support asynchronous coordination between a dispatcher and a traffic manager, the FAA has developed software that allows the flight operators to submit multiple, prioritized alternative flight plans. This set of alternative flight plans, submitted along with a filed route, is referred to as a Trajectory Option Set (TOS). And some airlines have now developed initial versions of software capable of generating and submitting such TOSs. This paper reports on cognitive walkthroughs with 5 dispatchers and 3 traffic managers on 5 scenarios designed to evaluate the operational concept, procedures and supporting FAA and airline software. The findings provide guidance for application of the concept of collaborative constraint propagation to support distributed work, as well as 42 recommendations for enhancing associated procedures and supporting software designs.

How Airline Dispatchers Manage Flights: A Task Analysis in Distributed and Heterogeneous Network Operations

Equipped with technology, airline dispatchers interact with multiple entities to maximize the safety and efficiency of flights. How well the overall airline system performs is influenced by dispatchers’ workload. In order to assist future work in developing advanced automated technologies to assist dispatchers, particularly under high-workload periods, this paper presents an analysis of airline dispatchers’ tasks in a large operations control center. This is an important step in developing airline dispatcher workload simulations and other analytical approaches that assist in staffing of operations for dynamic operations, as well as estimating the impact of new technology on dispatchers’ workload.

Sparring partners for human-in-the-loop simulations: the potential of virtual agents in air traffic simulations

A future challenge for the European air traffic system is an estimated rise in traffic load in combination with the occurrence of so-called disruptive events (e.g., thunderstorms, security alarms or union strikes). EUROCONTROL showed in their simulations that external events lead to instabilities in the whole European air traffic system with a weakened ability to recover [cf. (EUROCONTROL, Challenges of growth 2013—Task 6: the effect of air traffic network congestion 2035. EUROCONTROL, Brussels, 2013)]. Due to these events, EUROCONTROL estimates a strong increase of delay within the air traffic system, especially at the airports. Among various factors to keep the impact of these events minimized, a sufficient cooperation between the affected air traffic participants (pilots, controllers, airport staff, etc.) is necessary. Sharing information and aligning on a procedure to utilize the existing resources offers a way to efficiently keep up operations. A tool to train this cooperative behavior and to validate the benefits of new systems and procedures regarding the enforcement of cooperative behavior is a human-in-the-loop simulation (HITL). HITL simulations enable cooperative situations by facing the participants with disruptive events. These situations are commonly supported by so-called pseudo-actors, humans which take on one or multiple roles within the cooperation. Thereby the cooperation can be developed in a more or less challenging way. For instance, a delayed pilot reaction in dense traffic or an airline dispatcher not willing to cancel flights into a congested airport can be performed by a pseudo-actor. Currently, pseudo-actors with predefined instructions for their behavior are the only way to generate the above-mentioned challenges in HITL simulations. As human beings, the pseudo-actors show varying behavior. Therefore, reproducibility of the HITL simulation is limited, although being one of the key features. In contrast to field trials in a real environment all influencing factors of a HITL simulation are under control. Situations can be repeated multiple times. In terms of training simulation this is necessary to generate the intended learning effect. In terms of validation simulation the possibility to exactly repeat a situation is needed to compare a situation with the support of a new system (experimental condition) to one without the new system (baseline). This paper provides a contribution for assessing the potential of human pseudo-actor alternatives. Virtual agents are already used in other fields such as gaming and other types of simulation (e.g., virtual military training simulation). These virtual agents interact with the other human participants of the simulation. Moreover, as being computer applications, they strictly do follow their programmed behavior. Thus, they offer the benefit of reproducible behavior. The evaluation within this paper uses the airport management simulation of the German Aerospace Center to challenge four participants with multiple disruptive events. The role of the stand and gate allocation manager is either taken by a human pseudo-actor or a virtual agent. The results of the simulation runs with the human pseudo-actor are compared to the ones with the virtual agent. Analyzing the results a first conclusion on the potential of virtual agents in air traffic HITL simulations will be given.

Managing variability: a cognitive ethnography of the work of airline dispatchers

Airline dispatchers’ workflow is often described in broad terms like ‘flight planning’ and ‘flight following.’ Such high-level descriptions fail to recognize the number and complexity of tasks involved in these activities. An ethnographic study was conducted at three US airlines to understand the cognitive workload involved in flight planning. Fuel planning was identified as one of five key flight planning tasks. Fuel planning was conducted concurrently with other planning and monitoring tasks which often led to interruptions. Planning fuel was dynamic, with re-calculations required whenever other factors varied. This rework increased workload and opportunities for error while reducing efficiency. Beyond route changes, four main factors contributed variability to fuel planning: contingency planning, load planning, pilots, and station operations. Strategies for managing variability included pattern identification, use of buffers, rounding up, and leveraging software tools. Software design often added workload by forcing dispatchers to attend to low level tasks.

Fueling for contingencies: The hidden cost of unpredictability in the air transportation system

The aviation community is increasing its attention on the concept of predictability when conducting aviation service quality assessments. Reduced fuel consumption and the related cost is one of the various benefits that could be achieved through improved flight predictability. A lack of predictability may cause airline dispatchers to load more fuel onto aircraft before they depart; the flights would then in turn consume extra fuel just to carry excess fuel loaded. In this study, we employ a large dataset with flight-level fuel loading and consumption information from a major US airline. With these data, we estimate the relationship between the amount of loaded fuel and flight predictability performance using a statistical model. The impact of loaded fuel is translated into fuel consumption and, ultimately, fuel cost and environmental impact for US domestic operations. We find that a one-minute increase in the standard deviation of airborne time leads to a 0.88min increase in loaded contingency fuel and 1.66min in loaded contingency and alternate fuel. If there were no unpredictability in the aviation system, captured in our model by eliminating standard deviation in flight time, the reduction in the loaded fuel would between 6.12 and 11.28min per flight. Given a range of fuel prices, this ultimately would translate into cost savings for US domestic airlines on the order of $120–$452million per year.

Landing on empty: estimating the benefits from reducing fuel uplift in US Civil Aviation

Airlines and Air Navigation Service Providers are united in their goal to reduce fuel consumption. While changes to flight operations and technology investments are the focus of a number of studies, our study is among the first to investigate an untapped source of aviation fuel consumption: excess contingency fuel loading. Given the downside risk of fuel exhaustion of diverting to an alternate airport, airline dispatchers may load excess fuel onto an aircraft. Such conservatism comes at a cost of consuming excess fuel, as fuel consumed is a function of, among other factors, aircraft weight. The aim of this paper is to quantify, on a per-flight basis, the fuel burned due to carrying fuel beyond what is needed for foreseeable contingencies, and thereby motivate research, federal guidance, and investments that allow airline dispatchers to reduce fuel uplift while maintaining near zero risks of fuel exhaustion. We merge large publicly available aviation and weather databases with a detailed dataset from a major US airline. Upon estimating factors that capture the quantity fuel consumed due to carrying a pound of weight for a range of aircraft types, we calculate the cost and greenhouse gas emissions from carrying unused fuel on arrival and additional contingency fuel above a conservative buffer for foreseeable contingencies. We establish that the major US carrier does indeed load fuel conservatively. We find that 4.48% of the fuel consumed by an average flight is due to carrying unused fuel and 1.04% of the fuel consumed by an average flight is due to carrying additional contingency fuel above a reasonable buffer. We find that simple changes in flight dispatching that maintain a statistically minimal risk of fuel exhaustion could result in yearly savings of 338 million lbs of CO2, the equivalent to the fuel consumed from 4760 flights on midsized commercial aircraft. Moreover, policy changes regarding maximum fuel loads or investments that reduce uncertainty or increase the ability to plan flights under uncertainty could yield far greater benefits.

Modelling airline flight cancellation decisions

In order to predict airline responses to Traffic Management Initiatives (TMIs), and reveal the underlying preference structures that shape these responses, we study US domestic airlines’ cancellation decisions in response to the Federal Aviation Administration (FAA)’s TMIs, in particular, to Ground Delay Programs (GDPs). By observing the actual flight-cancellation choices made by airline dispatchers, the airlines’ cancellation utility functions can be inferred through the use of binary choice models. The model captures how delays to a given flight and potential delay savings to other flights affect flight cancellation decisions. We also find larger, fuller, less frequent, shorter-distance, and spoke-bound flights are less likely to be cancelled, and that there is inter-airline variation in flight cancellation behaviour.

Evaluation of Alternative Waypoint and Flight Plan Conventions for NextGen En Route Operations

This paper considers four alternative flight plan description conventions for use in the Next Generation Air Transportation (NextGen) program by airline dispatchers and compares each alternative against the current convention. The conventions included are: Fix and Route-based system (Fix/Route, i.e. the current convention), Geodetic Coordinates (GC), Navigation Reference System (NRS), Military Grid Reference System (MGRS), and Point Relation Navigation (PRN). Twenty-one airline dispatchers evaluated the conventions for ease of use, understanding, workload, and acceptability. The results identified the impact each convention had on participant performance, error commission, and user preference, on four tasks chosen to represent current dispatcher work practice. These tasks are more manual than those envisioned for future use, but would form the foundation for any fall-back operation. The study found that the existing Fix/Route convention had the best performance and lowest error rate and severity on the majority of tasks. Of the alternative conventions tested, the PRN and NRS conventions had similar performance to the Fix/Route convention, whereas the GC and MGRS conventions performed poorly compared with the Fix/Route convention. The dispatchers preferred the PRN convention to the other alternative conventions evaluated. The results of this study suggest that a successful replacement convention should use relative instead of absolute location specification; make use of some characteristics of the current airspace structure, such as the boundaries of the ARTCCs; and keep waypoint descriptors short or format them so that they can be combined into a single chunk in memory, which possibly can be associated with geographic meaning.

A Superior Tool for Airline Operations

The job of the airline dispatcher can be greatly enhanced with a new tool for making diversion decisions that satisfy safety and schedule needs.

Information Management to Support Distributed Decision-Making in the National Airspace System

For Summer 2000, the Federal Aviation Administration introduced a new collaborative procedure for reducing departure delays during weather events. This initiative involved the used of predefined Coded Departure Routes (CDRs). Goals of this procedure included: Providing airline operations centers and FAA air traffic facilities with a process for working collaboratively to develop earlier plans for dealing with predicted constraints. Giving airport control towers greater flexibility to respond to the often rapidly changing picture regarding available airspace during weather events. Keeping airline dispatchers in the loop through the early identification of alternative departure routes to expedite departures from an airport. An analysis of the use of CDRs was completed, based on interviews with staff at six airlines and four enroute air traffic control Centers, on analyses of System Command Center advisories and on analyses comparing filed with flown routes. Based on this analysis, recommendations are made for the design of improved tools for information dissemination and decision support.

Field Study to Evaluate Models of Team Decision-Making

Teams are often critical components of complex systems. Moreover, design of intelligent team training and aids depends on robust computational team models. To date, however, research has focused on computational models of individual decision-makers. No general computational team models exist. Models that do exist are typically quite primitive and restricted in domain of application. (Pew & Mayor, 1998) Thus, flexible, scalable, computational models of team decision making are urgently needed. In this paper, we describe a field study and proposed modeling extensions to the OFM/OFMspert methodology to represent team decision making. Specifically, this paper describes an initial extension of an OFM/OFMspert model for air traffic management (ATM), modeling the interaction between airline dispatchers and pilots-in-command of individual aircraft.

Cooperative Problem-Solving Challenges for the Movement of Aircraft on the Ground

In this paper, we discuss issues surrounding aircraft surface movement that were uncovered through a series of ethnographic investigations, including (a) observations of surface movement operations, (b) structured interviews with airline ramp control and dispatch personnel, and (c) critical incident reports. These results are part of the “problem identification” stage of a study aimed at the design of cognitive tools to improve the safety and efficiency of aircraft surface movement. This study is focusing on such issues from an airline operations control perspective (i.e., ramp control and dispatch). We have identified areas of opportunity for aiding airline staff and controllers in this information-intensive cognitive work, which will lead to identifying the nature of cognitive tools and procedures that could improve prioritization, planning, and coordination during surface movement

Using Forecasts of Future Incidents to Evaluate Future ATM System Designs

This paper describes and illustrates the use of a general methodology for knowledge elicitation to enable better prediction of the human factors implications of future system designs. Specifically, this approach involves the following steps:1. Identifying critical factors that could influence performance in the future system.2. Using this list of factors to predict incidents that could plausibly arise in the future system.3. Designing realistic, detailed incident reports based on these predicted incidents.4. Asking a group of experienced practitioners representing different perspectives in the current system to act as a review team by evaluating a reported incident and identifying the important issues and implications it raises.5. Using the insights generated by the discussions of the review team to provide guidance in making decisions about the implementation of the future system.To illustrate the use of this methodology, a scenario was developed. This scenario was based on experiences with the expanded National Route Program involving high-altitude crossing traffic (overflights) over departure and arrival lanes at a major airport. This already occurring situation was modified to fit the conditions of a future system in which en route Free Flight is allowed, and a hypothetical incident is predicted and described in detail in an incident report. A group including a pilot, two controllers, and an airline dispatcher was asked to act as a review team and evaluate this incident. The insights provided by the resultant discussion are presented. Many of these insights relate to issues concerning the roles and responsibilities of flight crews, controllers, traffic managers, and dispatchers. Others are concerned with the definition of procedures. Still others deal with issues of workload, training, maintenance of skills, and the communication of intent.

Control by Permission: A Case Study of Cooperative Problem Solving in the Interactions of Airline Dispatchers with ATCSCC

A 7-hour focus group session was held to explore issues concerning the interactions between airline operations control (AOC) and staff of the Air Traffic Control Systems Command Center (ATCSCC). This session was organized with three goals in mind:•To gain insight into the nature of the distributed and cooperative problem solving activities that arise in the interactions of the airlines with ATCSCC.•To identify the successful aspects of these interactions and to better understand the nature of underlying factors contributing to those successes.•To identify areas for potential improvement.Four factors were identified as contributing to successful cooperative problem solving: development of a shared understanding of goals and constraints, distribution of responsibilities, incorporation of feedback and process control, and staff selection. In addition, several areas for improvement were identified, including education, information exchange, policies and practices, work assignments, and computer support.