1. Introduction2. Overview of the U.S. air transportation system2.1 General description of the air transportation system1.1.1. Description1.1.2. Network description of the air transportation system2.2 History and evolution of the system2.2.1 System historical background, evolution, and architectural changes2.2.2 Current challenges facing the air transportation system3. Network analysis and system architecture3.1 Literature review3.2 Infrastructure Layer3.2.1 Single Layer Analysis Methodology3.2.2 Network Analysis Results3.3 Transport layer3.3.1 Methodology3.3.2 Results, interpretation and discussion3.4 Cross-Layer Analysis through Airports3.5 Cross-Layer Analysis through Navigational Infrastructure3.6 Demand layer3.6.1 Results4. Conclusion4.1 Summary of findings4.2 Implications of results from the network analysis to system architecture and potential architectural improvements5. Feedback on learning objectives5.1 Lessons learned5.2 Valuable aspects of system architectureESD.342 – Advanced System Architecture – Bonnefoy, Weibel PPrroojjeecctt AAiirr TTrraannssppoorrttaattiioonn SSyysstteemm AArrcchhiitteeccttuurree AAnnaallyyssiiss Philippe A. Bonnefoy Roland E. Weibel May 2006 (Image removed for copyright reasons.)ESD.342 – Advanced System Architecture – Bonnefoy - Weibel TTaabbllee ooff CCoonntteennttss 1. Introduction 3 2. Overview of the U.S. air transportation system 4 2.1 General description of the air transportation system 4 2.2 History and evolution of the system 6 3. Network analysis and system architecture 9 3.1 Literature review 9 3.2 Infrastructure Layer 10 3.3 Transport layer 13 3.4 Cross-Layer Analysis through Airports 17 3.5 Cross-Layer Analysis through Navigational Infrastructure 18 3.6 Demand layer 20 4. Conclusion 22 4.1 Summary of findings 22 4.2 Implications of results from the network analysis to system architecture and potential architectural improvements 22 5. Feedback on learning objectives 24 5.1 Lessons learned 24 5.2 Valuable aspects of system architecture 24 1ESD.342 – Advanced System Architecture – Bonnefoy - Weibel TTaabbllee ooff FFiigguurreess Figure 1. Stakeholders of the air transportation system ......................................................... 4 Figure 2. Network layers in the air transportation system...................................................... 6 Figure 3. Illustration of a Jet Route chart ............................................................................. 11 Figure 4: Degree Sequences of Jet Routes and Victor Airways........................................... 12 Figure 5. Wide body/Narrow body/Regional jet network and degree distribution .............. 14 Figure 6. Light Jet network and degree distribution............................................................. 15 Figure 7. Nodal (airport) interactions between scheduled and unscheduled traffic ............. 17 Figure 8: Betweenness Centrality of Navaids ...................................................................... 19 Figure 9. Airport rank vs. population basin size around the airport..................................... 21 LLiisstt ooff TTaabblleess Table 1: Selected Metrics for Airway Networks .................................................................. 13 Table 2: Network descriptive metrics of the scheduled air transport network..................... 15 Table 3: Network descriptive metrics of the unscheduled air transport network................. 16 Table 4: Summary of Shortest Path Characteristics ............................................................. 20 2ESD.342 – Advanced System Architecture – Bonnefoy - Weibel 11.. IInnttrroodduuccttiioonn The air transportation system is at a critical point in its history with growing demand for enhanced mobility, intense competition between carriers at both the national and international level, new aircraft types expected to enter service in the upcoming years (e.g. Very Light Jets, Unmanned Arial Vehicles), the lack of capacity at key points in the system, the growing concerns towards sustainability and environmental performance, etc. The air transportation system is a woven set of networks, which we will call system layers. A full system description includes many different layers, capturing demand for service by people and goods, routes flown by aircraft, and the infrastructure utilized by aircraft. These layers will be structured and explained in the following section, and three layers are used for more detailed analysis. The resulting overall topology of the networks has great implications on the ability of the system to respond to disturbances (e.g. environment related such as weather, voluntary attacks such as terrorist attacks, etc.), adapt to changes (e.g. introduction of new type of aircraft or business models, etc.) that ultimately influence its overall performance. This project is aimed at broadening the understanding of the structure, properties, dynamics of the air transportation network and anticipating the implications of changes -key trends in the system- and policies on the performance of the system. It is anticipated that the network analysis of the air transportation system will provide insight into its current architecture and to potential future architectures. 3ESD.342 – Advanced System Architecture – Bonnefoy - Weibel 22.. OOvveerrvviieeww ooff tthhee UU..SS.. aaiirr ttrraannssppoorrttaattiioonn ssyysstteemm 2.1 General description of the air transportation system 1.1.1. Description The Air Transportation System is an interconnected system of infrastructure and service providers that is aimed at providing transportation by air to people and freight. Figure 1 represents the stakeholders in the air transportation system: The major actors are the air transportation providers (e.g. airlines, regional carrier operators, fractional ownership operators, etc.) who represent the interface between the foundations of the system (the National Airspace System) and the passengers and freight that are transported. The National Airspace System is the critical subpart of this overall system that is defined as the interconnected system of airports, airways, air traffic facilities and navigational aids. These elements of the NAS are operated and supported by airport employees, air traffic controllers, technicians, airspace specialists, and others. Airports, air