Air Traffic Control Center Research Articles

Repairs as the last orderly provided defense of safety in aviation

We analyze the multi-dimensional organization of action in aviation, focusing on the repairs that derive from parties’ orientation to several sources of knowledge in which current information provides corrections for errors occurring earlier at the organizational and local levels. We suggest that the analysis of the coordination of talk and action can inform us about the multi-dimensional nature of the organization of action in complex environments. We note that repairs and corrections in naturally occurring activities inform participants and researchers about troubles that do not, however, cause incidents or accidents thanks to these corrective practices. The multi-dimensional organization of actions provides a number of corrective resources against emerging incidents. Our video-taped data comes from two environments, air traffic control centers and simulated Airbus flights, including more than 70 h of data in all. The sequential analysis of talk and action is based on conversation analysis (CA), ethnomethodology (EM), and ethnographic field work. The theoretical aims of the study concern the explication of organization of complex multimodal activities in which talk, action and technical resources are interwoven. In practical terms, the study aims at making the emergence and management of errors in complex activities transparent, providing a basis for improving safety procedures.

Understanding aviation English as a lingua franca

Researchers exploring the use of language use in radiotelephony communication have tended to focus on the limitations of the non-native English user and the threats which their limited control of English may pose for aviation safety (e.g. Atsushi, 2003, 2004). Hence the recent International Civil Aviation Organization (ICAO) policy places the onus on non-native users to bring their English to an appropriate standard. The present paper argues that there is a need for a broader perspective on this issue and supports this case with reference to two sources of data: a) episodes of radiotelephony discourse recorded in two air traffic control centres in Korea exemplifying non-routine, abnormal and emergency situations involving NS of English and NNS from different language backgrounds, b) focus group and individual interviews with selected Korean aviation personnel eliciting their interpretations of these episodes and of issues in aviation English more generally. Findings suggest that responsibilities for communication problems in aviation English are distributed across NS and NNS users, and may be partly due to the absence of shared assumptions about efficient and appropriate communication practices in an environment where English is a lingua franca (ELF). Implications are drawn for the communication training of all aviation personnel, regardless of language background.

Understanding Aviation english as a Lingua Franca

Researchers exploring the use of language use in radiotelephony communication have tended to focus on the limitations of the non-native English user and the threats which their limited control of English may pose for aviation safety (e.g. Atsushi, 2003, 2004). Hence the recent International Civil Aviation Organization (ICAO) policy places the onus on non-native users to bring their English to an appropriate standard. The present paper argues that there is a need for a broader perspective on this issue and supports this case with reference to two sources of data: a) episodes of radiotelephony discourse recorded in two air traffic control centres in Korea exemplifying non-routine, abnormal and emergency situations involving NS of English and NNS from different language backgrounds, b) focus group and individual interviews with selected Korean aviation personnel eliciting their interpretations of these episodes and of issues in aviation English more generally. Findings suggest that responsibilities for communication problems in aviation English are distributed across NS and NNS users, and may be partly due to the absence of shared assumptions about efficient and appropriate communication practices in an environment where English is a lingua franca (ELF). Implications are drawn for the communication training of all aviation personnel, regardless of language background.

Modeling and Optimization in Traffic Flow Management

Traffic flow management (TFM) allocates the various airport, airspace, and other resources to maintain an efficient traffic flow consistent with safety. TFM is a complex area of research involving the disciplines of operations research, guidance and control, human factors, and software engineering. Hundreds of human operators make TFM decisions that involve tens of thousands of aircraft, en route air traffic control centers, the Federal Aviation Administration's System Command Center, and many airline operation centers. This paper provides an overview of how TFM decisions are made today and challenges facing the system in the future, and reviews modeling and optimization approaches for facilitating system-wide modeling, performance assessments, and system-level optimization of the national airspace system in the presence of both en route and airport capacity constraints.

A system of flight data acquisition, processing, and recording

A system for recording and analysis of flight information including the technical condition of a control object and the state of its controller’s health in real time aboard a flight vehicle and in ground-based air traffic control centers is described.

An observation tool to study air traffic control and flightdeck collaboration

The complex systems of the flightdeck (FD) and the Air Traffic Control Centre (ATC) are characterised by numerous concurrently operating and interacting communication channels between people and between people and machines/computer systems. This paper describes work in support of investigating the impact of changes to technologies and responsibilities within this system with respect to human factors. It focuses primarily on the introduction of datalink (text-based communication rather than traditional radio communication) and the move towards freeflight (pilot-mediated air traffic control). Air traffic management investigations have outlined these specific changes as strategies to enable further increases in the volume of air traffic. A systems approach was taken and field studies were conducted. Small numbers of domain experts such as air traffic controllers (ATCOs) were involved in the field-based observations of how people interact with systems and each other. This paper summarises the overall research approach taken and then specifically reports on the field-based observations including the justification, development, and findings of the observation tool used. The observation tool examined information propagation through the air traffic control-flightdeck (ATC–FD) system, and resulted in models of possible information trajectories through the system.

Organizational climate in air traffic control: Innovative preparedness for implementation of new technology and organizational development in a rule governed organization

A positive and innovative organizational climate is of great importance in order to manage and adapt to change. Such a climate seldom evolves in organizations closely governed by rules and regulations. Because of ongoing organizational and technical changes within the Swedish Air Navigation Services Provider, a study concerning the organizational climate for changes and innovations was conducted to investigate the organization's capacity to cope with changes. Study locations were the two Swedish main air traffic control centers and parts of the civil aviation administration headquarters. In the study 390 subjects took part and the CCQ questionnaire was used to measure the organizational climate. The results show that the organizational climate is quite positive despite the rule-governed work. The results also show that administrative personnel assess the organizational climate as more positive than operative personnel. Comparisons between management positions did not result in any differences.

Reliability of base isolation for the protection of critical equipment from earthquake hazards

As the number of critical facilities such as data centers, Internet collocation facilities, hospitals, and air traffic control centers continues to grow, the sensitivity of expensive vibration sensitive equipment in these facilities to earthquake hazards is becoming a pressing concern. This paper addresses the seismic risk analysis of critical facilities by specifying the required reliability of components of vibration isolation systems for an improved performance and reliability of isolated sub-systems with respect to earthquake hazards. A four-story structure representing a critical facility with an isolation floor at the second floor level, carrying a computer rack, representing shock and vibration sensitive equipment, is considered in order to study the reliability requirements of isolation system components for the protection of the critical equipment from earthquake hazards. Including uncertainties such as isolation system characteristics, i.e. isolation stiffness and isolation damping, eccentricity in the superstructure, and ground motion characteristics along with 3D models subjected to bi-directional ground motions, allows us to represent the nature of the problem in a realistic way. Because of the complexity of the system and the analysis, and the difficulty of completely describing the probabilistic characteristics of the whole process analytically, the Monte Carlo simulation technique is used to determine probability distributions and failure probabilities.

ASAS: From Concept to Reality

The increasing congestion in the skies of Europe with the attendant delays and costs are well known. By 1999 many studies were being performed on prospective solutions. In that year, a consortium of equipment suppliers, research organisations and service providers considered that none of the individual studies alone could address the problems and that a complete gate-to-gate philosophy was needed, including 4D applications and Airborne Separation Assistance. Thus the MA-AFAS (More Autonomous Aircraft in the Future ATM System) programme was born to investigate a more general solution to the problem. MA-AFAS was part funded by the European Commission under the Fifth Framework Programme, New Perspectives in Aeronautics. MA-AFAS was focused mainly on the airborne side, building previous research on specific aspects of capacity and safety enhancement into an integrated solution that was flown in a very successful series of live trials.On March 25, 2003, two airliners were positioned at the same height on intersecting tracks over the Mediterranean Sea between Rome and Sardinia. The future conflict was observed by an air traffic controller at Roma Air Traffic Control Centre who instructed one of the aircraft to pass behind the other at a distance of 6 nautical miles. The Flight Management System in the aircraft automatically generated an optimal conflict resolution, in accordance with the instruction, and then guided the aircraft through the manoeuvre. Over the following three days during trial flights for the MA-AFAS programme, this manoeuvre and others were successfully repeated, causing pilots and controllers to remark that it had become routine. ASAS was in the air and working.

First of a new generation of European air traffic control centres now operational

First of a new generation of European air traffic control centres now operational

Operator-centred local error management in air traffic control

Introduction: A large number of air traffic control occurrences take place without resulting in loss of separation between aircraft. Unfortunately such occurrences are seldom reported and therefore not used for disclosing system weaknesses, such as inappropriate methods and procedures. The ATCC (Air Traffic Control Centre) Malmoe made a trial with local reporting of “learning occurrences”. The trial was ATCO-(Air Traffic Controller) centred. The study objectives were to evaluate if ATCOs would start to report after a defined training and marketing effort, if they could identify system weaknesses, if concrete actions for safety improvement would be taken as a result of the trial and to what extent expert support was necessary. Method and material: The trial period was eight months. The ATCO report would be made on a simple form, available on site. These reports would then be analysed in groups and the marketing and feedback efforts would be co-ordinated by the local flight safety group. Results: 43 reports were filed and analysed during the trial period. The initial motivational training and marketing was considered adequate. During the group discussions, the ATCOs identified system weaknesses within 40 of the reports. The resulting safety improvement actions included: the ATCC unit becoming more active in contacting the pilots and airline companies, the renaming of some waypoints (due to name similarities), the implementation of safer procedures when relieving ATCOs, the training of ATCOs in cockpit flight management systems, and the initiation of a research project primarily concerned with ATCO mental overload. Expert support was required in the beginning to help ATCOs focus on the system rather than on the individual.

Performance Metrics for Oceanic Air Traffic Management

The Federal Aviation Administration (FAA’s) Oceanic and Offshore Integrated Product Team is developing a set of performance metrics and identifying methodologies for calculating them. These metrics will be used to benchmark and measure how well the FAA’s Oceanic Air Traffic Control Centers are meeting their goals and priorities, and delivering oceanic air traffic services and benefits.There are many challenges that must be addressed to meaningfully measure and evaluate the oceanic system performance. Some of these challenges are the same as those for measuring the performance of the National Airspace System (NAS) as a whole. However, since many oceanic flights start or end in other countries, there are additional challenges in obtaining the data necessary to calculate the oceanic performance metrics.The FAA’s Air Traffic Services (ATS) organization identified a set of system performance outcomes in the areas of safety and operation efficiency (e.g., predictability, flexibility, delay, and access). Oceanic airspace users indicated their priority areas as safety, on-time performance, fly as filed, flexibility, and fuel consumption. The oceanic performance metrics have been developed to measure the ATS outcomes and the users’ priorities. In addition, environmental factors (e.g., flight count, aircraft avionics equipage) that affect the service delivery are included to provide a proper context for the metrics.The oceanic metrics are collected in a “dashboard” to provide a general picture of the overall service quality provided to oceanic airspace users. A dashboard is generated for each of the New York and Oakland Oceanic Centers, as well as for sub-regions in each Center to account for the air traffic characteristics unique to that sub-region.This paper presents example analyses and results obtained for environmental and performance metrics for New York and Oakland Oceanic Centers, and shows how the metrics can be used to monitor the performance of air traffic management services provided to oceanic airspace users.

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.

Applications of multirate optical fibre code-division-multiplexing systems to high-speed data communications for air traffic control

AbstractFuture air traffic control will be based on the distributed processing environment. This leads to the use of high-speed optical fibre networks and systems to connect many processors (for both general and specific purposes) and workstations in the air traffic control centres. To efficiently support such applications, communication systems should be capable of multirate operations. To achieve this aim, we propose an efficient optical fibre code-division multiplexing (OF-CDM) technique that can support multirate data communications without any increase of system complexity when compared with the equal-rate operation case. Unlike conventional optical orthogonal codes (OOCs), the use of our proposed unequal-length OOCs can eliminate any possible violation of the minimum cross-and auto-correlation constraint (i.e. ‘1’) in multirate OF-CDM systems. Thus, using unequal-length OOCs can achieve a better bandwidth efficiency and a lower bit error rate for multirate transmissions than employing conventional OOCs. Moreover, we present the design of cost-effective OF-CDM transmitters for multirate data transmissions. The proposed systems can be also employed to support future airborne real-time data distributions and computer interconnects.

Air Traffic Controller Trust in a Conflict Probe during Free Flight

Many Air Traffic Control (ATC) workstations include or will include conflict probes to detect situations where aircraft threaten to approach too closely. Conflict probes have been tested at ATC centers. The free flight (FF) concept may increase pilots' ability to make realtime choices regarding their own flight paths. The resulting traffic complexity will require better automated conflict detection, but FF may limit the utility of a conflict probe, since pilots may resolve their own conflicts - or create new ones. This paper examines the impact of conflict probes on controller trust and behavior under FF as well as under current ATC procedures.

An Index of Dynamic Density

The risk of a collision between aircraft is rising as the density of commercial air traffic increases. This trend, together with the overwhelming need to upgrade the National Airspace System, has motivated the Federal Aviation Administration to sponsor the development of metrics to evaluate “dynamic density”—a proxy for the likelihood of collision risk. Here we propose and evaluate a mathematical index of dynamic density, D, that describes collision risk. Although our domain of investigation is aviation, the logic of D is applicable whenever objects move in limited spaces. A series of sensitivity analyses illustrate how D responds to frequently encountered air traffic conflict situations. We illustrate a use of D that characterizes pilot performance and efficiency in experimental simulations of free flight and suggest other human factors applications. This research could be applied immediately by the traffic management units of en-route air traffic control centers to reformulate the criterion for the critical capacity of sectors.

Basic functional requirements and results for an MSSR on-site evaluator based on RF target injection

Modern quality control in radar systems is based on the input of known signals into the radar chain. These signals are used in a remote air traffic control centre to determine the current parameters of the radar system. In this framework, the paper describes the functional requirements of a monopulse secondary surveillance radar (MSSR) evaluator based on RF target injection. In particular, those aspects concerning the reply generation function are described. The azimuth of the emulated plot can be affected by different error sources which are not due to the radar extractor but are related to the generation and injection process. Errors in the amplitude and phase of Σ and Δ result in azimuth errors and must be kept to a minimum. Synchronisation with the turn of the antenna will also lead to unavoidable azimuth errors. These error sources are studied, and three different data analyses carried out on real radar are also presented.

A Cognitive Model of En-Route Air Traffic Control

Two extensive series of experiments were conducted with Air Traffic Controllers (ATCO's) from the Berlin Air Traffic Control Centre (BARTCC) to investigate controllers' information intake and cognitive representation. Their results served as an empirical base for the cognitive model. The model describes at a representational level the cognitive functions and attentional processes underlying the task compliance. It contains a hybrid architecture, which is built up by an analogue of the spatial radar screen information. One subsequent experiment was conducted to evaluate predictions of the model. During a running simulation future positions of aircrafts (AC's) had to be anticipated by eight ATCO's. The results are discussed.

Combating terrorism against commercial aviation

General concern about terrorism and sabotage in the United States has grown in the aftermath of the sabotage of Amtrak in Arizona, the bombing of the federal office building in Oklahoma City, the bomb threat at the New York regional air traffic control center, and the bombing of the World Trade Center. A concomitant concern has developed with regard to the adequacy of security at domestic airports and in commercial aviation. Twice in a three month period in 1995 the Federal Aviation Administration (FAA) increased airport security. In August 1995, the ordered heightened airport security procedures due to concern within the Clinton Administration about the threat of more frequent and more deadly terrorist attacks in the United States. (1) Then, in October 1995, the once again increased airport security due to concern about the visit of Pope John Paul II, progress in the Palestinian and Israeli peace process, and the conviction of ten Muslim terrorists. Concern with the security of commercial aviation reached an all-time high after the bombing of Pan Am Flight 103 over Lockerbie, Scotland in December 1988. This deadly act of terrorism prompted passage of the Aviation Security Improvement Act of 1990 (1990 Act) which set a number of goals for the enhancement of commercial aviation security. In the early 1990s concern seemed to ebb as acts of terrorism against U.S. targets decreased only to be heightened by the events in Oklahoma City and the explosion aboard TWA Flight 800 in July 1996. (2) There was a realization that terrorists are finding targets in the United States more attractive and attacks on the traveling public were likely to increase. Heightened commercial aviation security, while good for the safety of the traveling public, is not without its costs. Besides the direct costs associated with employing additional security personnel and are the indirect costs--the opportunity costs--associated with the inevitable delays that accompany more careful screening of passengers and their luggage. Tighter security requires the traveler to allot more time to make flights because curbside check-in is not available, metal detectors are more sensitive leading to more false alarms, more luggage is searched, and gate agents are asking passengers more questions. (3) The obvious question is whether the benefits gained from enhanced aviation security justify the costs. During the first part of the 1990s strides have been made in the improvement of commercial aviation security in the United States. Despite these advancements, there is a lot yet to be done. This paper provides an overview of developments in commercial aviation security in the United States during the first part of the 1990s, discussing the accomplishments and setbacks encountered, and outlines the challenges that remain. BACKGROUND The has responsibility for the safety and security of commercial aviation in the United States. The FAA's approach to ensuring security in commercial aviation has evolved over the years in response to changes in the complexion and frequency of terrorism. The bombing of Pan Am Flight 103 heightened concern about the security of commercial aviation to such an extent that Congress passed the Aviation Security Improvement Act of 1990. The 1990 Act underscored concern about aviation security shared by Congress and the general public. It contained many mandates and directives for the including: * FAA and the FBI were required to jointly assess the threats to and vulnerabilities of the nation's airports * was required to review the security programs of foreign air carriers and approve those that provide a level of protection similar to that provided by U.S. carriers serving the same airport * was required to study the need for additional measures to safeguard the transportation of cargo and mail by passenger aircraft * was directed to support the acceleration of research to develop explosive detection equipment (4) It was hoped these measures would greatly improve commercial aviation security in the U. …

A new underground air traffic control centre for Oslo : B. Bakkejord & J. B. Hoyer, Tunnelling & Underground Space Technology, 10(2), 1995, pp 169–177

A new underground air traffic control centre for Oslo : B. Bakkejord & J. B. Hoyer, Tunnelling & Underground Space Technology, 10(2), 1995, pp 169–177