Air traffic demand is growing. New methods of airspace design are required that can enable new designs, do not depend on current operations, and can also support quantifiable performance goals. The main goal of this thesis is to develop methods to model inherent safety and control cost so that these can be included as principal objectives of airspace design, in support of prior work which examines capacity. The first contribution of the thesis is to demonstrate two applications of airspace analysis and design: assessing the inherent safety and control cost of the airspace. Two results are shown, a model which estimates control cost depending on autonomy allocation and traffic volume, and the characterization of inherent safety conditions which prevent unsafe trajectories. The effects of autonomy ratio and traffic volume on control cost emerge from a Monte Carlo simulation of air traffic in an airspace sector. A maximum likelihood estimation identifies the Poisson process to be the best stochastic model for control cost. Recommendations are made to support control-cost-centered airspace design. A novel method to reliably generate collision avoidance advisories, in piloted simulations, by the widely-used Traffic Alert and Collision Avoidance System (TCAS) is used to construct unsafe trajectory clusters. Results show that the inherent safety of routes can be characterized, determined, and predicted by relatively simple convex polyhedra (albeit multi-dimensional and involving spatial and kinematic information). Results also provide direct trade-off relations between spatial and kinematic constraints on route geometries that preserve safety. Accounting for these clusters thus supports safety-centered airspace design. The second contribution of the thesis is a general methodology that generalizes unifying principles from these two demonstrations. The proposed methodology has three steps: aggregate data, synthesize lean model, and guide design. The use of lean models is a result of a natural flowdown from the airspace view to the requirements. The scope of the lean model is situated at a level of granularity that identifies the macroscopic effects of operational changes on the strategic level. The lean model technique maps low-level changes to high-level properties and provides predictive results. The use of lean models allows the mapping of design variables (route geometry, autonomy allocation) to design evaluation metrics (inherent safety, control cost).

Generic airspace, or air traffic control sectors with similar operational characteristics, is an operational concept being proposed as a means of increasing staffing flexibility and reducing training times as part of the Federal Aviation Administration’s (FAA’s) Next Generation (NextGen) air traffic control (ATC) modernization efforts. A key need for implementing generic airspace is identifying groups of similar sectors with respect to training required for controllers to make transitions between those sectors. Through the development and validation process of the studies performed in this thesis, a structure-based classification scheme was found to be an effective way to classify sectors in order to support a minimal differences training approach to generic airspace. The resulting classes of sectors are expected to have fewer transition barriers and support increased staffing flexibility. In order to assess similarities of airspace sectors, factors affecting how easily a controller makes a transition from one sector to another were identified using semi-structured interviews with experienced air traffic controllers. The most important factors appear to reflect familiarity with types of operations and common traffic patterns, providing a basis for classifying groups of sectors. The controllers identified some techniques that are easily transferable as well. Some factors that are very specific to transitions were identified as well, such as “knowing the neighbor sectors” and “coastal area” factors. Based on the most important factors, traffic patterns in 404 high-altitude National Airspace System (NAS) sectors were examined for common traffic patterns. These traffic patterns were used as the basis for two classification approaches, a holistic classification approach and a decompositional classification approach. These approaches are used to classify current air traffic control sectors into classes with common structural characteristics. The results identify existing sectors with near-term potential as being generic sectors that support a minimal differences training approach to generic airspace. Further analysis with the sector classification results identified that the number of factors incorporated in the classification methods are directly associated with the method's effectiveness. In order to examine the validity of the developed classification methods and to assess the relative importance of the factors involving transitions identified by the interviews, an online survey was conducted with 56 air traffic controllers. The results indicated that the classification methods developed support controllers' perception of airspace similarities. Some qualitative data gained from the survey provides an insightful aspect for future steps continuing this study such as additional important factors to be considered. Some of these factors are considered as part of the classification schemes developed in this thesis while some are yet to be incorporated. Some of these additional factors were found to be more feasible to be incorporated into future classification schemes than other factors.

Generic airspace, or air traffic control sectors with similar operational characteristics, is an operational concept being proposed as a means of increasing staffing flexibility and reducing training times as part of the Federal Aviation Administration’s (FAA’s) Next Generation (NextGen) air traffic control (ATC) modernization efforts. A key need for implementing generic airspace is identifying groups of similar sectors with respect to training required for controllers to make transitions between those sectors. Through the development and validation process of the studies performed in this thesis, a structure-based classification scheme was found to be an effective way to classify sectors in order to support a minimal differences training approach to generic airspace. The resulting classes of sectors are expected to have fewer transition barriers and support increased staffing flexibility. In order to assess similarities of airspace sectors, factors affecting how easily a controller makes a transition from one sector to another were identified using semi-structured interviews with experienced air traffic controllers. The most important factors appear to reflect familiarity with types of operations and common traffic patterns, providing a basis for classifying groups of sectors. The controllers identified some techniques that are easily transferable as well. Some factors that are very specific to transitions were identified as well, such as “knowing the neighbor sectors” and “coastal area” factors. Based on the most important factors, traffic patterns in 404 high-altitude National Airspace System (NAS) sectors were examined for common traffic patterns. These traffic patterns were used as the basis for two classification approaches, a holistic classification approach and a decompositional classification approach. These approaches are used to classify current air traffic control sectors into classes with common structural characteristics. The results identify existing sectors with near-term potential as being generic sectors that support a minimal differences training approach to generic airspace. Further analysis with the sector classification results identified that the number of factors incorporated in the classification methods are directly associated with the method's effectiveness. In order to examine the validity of the developed classification methods and to assess the relative importance of the factors involving transitions identified by the interviews, an online survey was conducted with 56 air traffic controllers. The results indicated that the classification methods developed support controllers' perception of airspace similarities. Some qualitative data gained from the survey provides an insightful aspect for future steps continuing this study such as additional important factors to be considered. Some of these factors are considered as part of the classification schemes developed in this thesis while some are yet to be incorporated. Some of these additional factors were found to be more feasible to be incorporated into future classification schemes than other factors.

Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Includes bibliographical references. / M.S.

Rapid technological change and increasing traffic volumes worldwide are adding to the safety challenges for air traffic control. The night shift has traditionally been a period of low workload and work practices have evolved to reflect this. Thus, despite the exemplary safety record, there is a need to consider further systemic defences for maintaining performance and safety on the night shift. One possible strategy is the provision of a scheduled nap at work. In order to investigate the consequences of a scheduled nap on the night shift, 28 operational air traffic controllers were monitored across four roster cycles. Each roster cycle included one of two night shifts. Air traffic controllers were given a nap opportunity on one night shift of each type, and did not nap on the other. Information on the timing, quantity, and quality of sleep during the work week and days off was collected using actigraphy, and supported with logbook data. Sleep during the nap was measured using polysomnography, and the EEG and EOG were further utilised to determine neurophysiological alertness over the latter part of the night shift. Reaction time performance was measured three times across the night shift (beginning, middle, and end) with the psychomotor vigilance test.Actigraphy data indicated that the backward, rapidly-rotating work schedule of air traffic controllers resulted in a progressive loss of sleep across the work week. The reduction in sleep lead to an increasing cumulative sleep debt that was at a maximum prior to the night shift. This sleep debt was not related to reaction time performance at the end of the night shift, but was found to influence neurophysiological alertness.It was determined that the large majority of air traffic controllers were able to sleep during the scheduled 40 minute nap opportunity. However, the latency to sleep onset was long, the sleep short, and of relatively poor quality. Circadian and homeostatic factors increased the likelihood of entry into, and waking from, slow wave sleep (SWS). They were also found to influence reaction time performance and neurophysiological alertness. More variable performance and lowered alertness were seen at the end of the later starting (and finishing) night shift, possibly due to the combined influence of circadian and time-on-task factors. Homeostatic variables had less influence on performance at the end of the night shift, but greater acute sleep loss and higher cumulative sleep debts were related to increased neurophysiological sleepiness.performance and greater neurophysiological alertness in a dose-dependent manner, with even small amounts of stage 1 sleep effecting a performance improvement. Performance improvement was consistent across a range of reaction time measures and consistent improvements were also evident in the neurophysiological data, with the occurrence of SEMs declining, and lower spectral power evident in all frequency bands and single frequencies.These findings clearly demonstrate that a minimal quantity of sleep benefits the performance and alertness of air traffic controllers despite the "noise" of a field setting, thus providing a link between laboratory studies of napping and the actual work environment. The findings also fully support management endorsing a 40 minute napping opportunity for air traffic controllers working the night shift.The short nap sleep had no measurable effect on sleep subsequent to the night shift. However, the amount of sleep obtained in the nap was related to improved reaction time.

Background: In Sweden, air traffic control is currently performed in a mo-nopoly with the state owned Luftfartsverket as the only sup-plier. A deregulation process has been initiated with the ration-ale of cost reductions, both for airports and airline passengers. Problem and purpose: Economic arguments have been predominant for this potential deregulation and the underlying assumptions are that private al-ternatives would improve efficiency and reduce costs. This has lead the authors to identify what private alternatives would do differently than the current public operator in order to offer these benefits. Method: To fulfill the purpose the authors have used a qualitative ap-proach based on interviews with the current public operator as well as a new potential private alternative. In addition to this, interest organizations and regulative agencies have been con-tacted and secondary data incorporated to provide a holistic perspective. Conclusion: The authors have identified differences in activities between a public and private alternative that would create an advantageous effect on the market. They are: a different management of re-tirement funds, prolonged retirement age, new compensation system, altered recruitment policy, a full utilization of staff and a seizing of non-value adding activities.

Radiotelephony between air traffic controllers and pilots utilises standard phraseology as the medium of communications. Standard phraseology employs specific structure, terminology and pronunciation to ensure effectiveness and accuracy. On occasions when standard phraseology is found insufficient, plain language is used to efficiently relay vital information. By default, English is the designated language of communication between controllers and pilots of international flights. Deviations from the usage of standard phraseology and lack of language proficiency had been identified as one of the causal factors in safety occurrences. Language deficiencies, specifically of the non-native speakers of the English language, had raised much concern but there is limited information in the area. This research attempted to fill a small segment of this knowledge gap. It was focussed on the usage of standard phraseology and English language in an air traffic control environment involving English Second Language users. Audio data was sourced from routine radiotelephony recordings of ‘live’ air traffic control facilities in Malaysia to capture realistic communications between controllers and pilots in the Terminal Approach Radar, Area Radar and Aerodrome Control environments. A detailed cross sectional investigation of the radiotelephony characteristics, deficiencies and errors of transmitted messages revealed the radiotelephony performances of controllers and pilots in the environments. The recurrence of deviations from standards and occurrence of errors implied the likelihood of such deficiencies taking place. Demographic groups’ descriptions complemented the radiotelephony analyses as background information on language related training. The results were comparative to other similar studies and offered new information on English Second Language speakers in the Air Traffic Control environment.

<p>Background:</p><p>In Sweden, air traffic control is currently performed in a mo-nopoly with the state owned Luftfartsverket as the only sup-plier. A deregulation process has been initiated with the ration-ale of cost reductions, both for airports and airline passengers.</p><p>Problem and purpose:</p><p>Economic arguments have been predominant for this potential deregulation and the underlying assumptions are that private al-ternatives would improve efficiency and reduce costs. This has lead the authors to identify what private alternatives would do differently than the current public operator in order to offer these benefits.</p><p>Method:</p><p>To fulfill the purpose the authors have used a qualitative ap-proach based on interviews with the current public operator as well as a new potential private alternative. In addition to this, interest organizations and regulative agencies have been con-tacted and secondary data incorporated to provide a holistic perspective.</p><p>Conclusion:</p><p>The authors have identified differences in activities between a public and private alternative that would create an advantageous effect on the market. They are: a different management of re-tirement funds, prolonged retirement age, new compensation system, altered recruitment policy, a full utilization of staff and a seizing of non-value adding activities.</p>

Runway incursions (RWYI) are a daily phenomenon in the world and is a threat to safety. The severity of a RWYI can be high and it is a problem that is subject to improvements. The purpose of this report is to present the findings after an investigation of RWYI in general and what is being done to prevent it in Sweden. The main focus is to present the problem from an air traffic controller (ATCO) and pilot perspective. However, we are also presenting all the different stakeholders involved in the problem followed with associated risks and means to prevent a RWYI from happening. We also present technical aids and working methodology used today in air traffic control towers in Sweden and in addition some technology implemented abroad. Some suggested improvements that the stakeholders can take into consideration when developing their work to reduce the risk for a RWYI is also presented. The method used during the investigation has mainly been literature studies, interviews with different stakeholders and study visits to Bromma tower, Arlanda tower and SAAB/Linköping tower. We have found that the pilots and vehicle drivers are the most contributing stakeholders to a RWYI in Sweden. The investigation also shows that ATCOs and pilots share some opinions regarding risks but also improvements. Both ATCOs and pilots agree that weather with bad visibility, as well as darkness, is increasing the risk for an incident or accident to happen. Furthermore, complacency, fatigue and tiredness are also risks that are shared between ATCOs and pilots. We have also found that airports have different means to prevent a RWYI. At Arlanda, the ATC system is well developed with electronic equipment and stop bars at the taxiways, which is not the case for either Bromma or SAAB/Linköping airport. Even pilots in different airlines operate differently when about to enter a runway and there is no standard operating procedure (SOP) developed in all companies. Some of the suggested improvements are to implement stop-bars on every airport and that it should be mandatory to equip vehicles operating on the maneuvering area with maps.

Thesis (M.S.)--Ohio University, June, 2003. / Title from PDF t.p.