Efficient speed advisories for multi-stage-metering arrival management

This paper presents a methodology and algorithm for Air Traffic Control (ATC) to efficiently achieve schedules arrival times through speed control in the presence of uncertainty. The methodology does not assume the availability of airborne time of arrival control and can therefore be applied to legacy aircraft. The speed advisories are calculated in a manner that allows for sufficient control margin to, if required, adjust the aircraft's trajectory at a later stage to correct for estimated arrival time drift at the lowest impact to efficiency. The methodology is therefore envisioned to prevent major last-minute interventions and instead assists ATC in allowing more continuous descent approaches to be conducted by aircraft leading to more efficient operations

Effects in fuel consumption of assigning RTAs into 4D trajectory optimisation upon departures

ATACCS Conference - Boeing Best PhD Paper Award. SESAR HALA! network (2013-05-31 )4D trajectory optimisation has showed good potential to reduce environmental impact in aviation. However, a recurrent problematic is the loss in air traffic capacity that these pose, usually overcome with speed and time advisories. This paper aims at the quantification in terms of fuel consumption of implementing suboptimal trajectories to preserve capacity. Via an own developed optimisation framework, we deliver results on how imposing a nonoptimal RTA to a trajectory increases the fuel burned. We show how advancing a metering fix in an example departure trajectory translates to an increase of up 15Kg of fuel burned. Similarly, postponing it 50s, will burn around 23Kg more. Also, imposing a level off phase (due to incoming traffic) will typically consume around 25Kg more. Different scenariosAward-winningPostprint (published version

Neutral description and exchange of design computational workflows

Proposed in this paper is a neutral representation of design computational workflows which allows their exchange and sharing between different project partners and across design stages. This is achieved by the de-coupling of configuration and execution logic. Thus, the same underlying workflow can be executed with different (fidelity) models and different software tools as long as the inputs and outputs of the constituent process are kept the same. To this purpose, an object model is proposed to define different simulation objects, their scope, and hierarchy in the simulation process. An XML based computer readable representation of workflows based on the proposed object model, is also suggested. The application of the proposed representation is demonstrated via a case study involving the exchange of workflows between two design partners. The case study also demonstrates how the same workflow can be executed using different execution tools and involving different fidelity models

Design Analysis of Corridors-in-the-Sky

Corridors-in-the-sky or tubes is one of new concepts in dynamic airspace configuration. It accommodates high density traffic, which has similar trajectories. Less air traffic controllers workload is expected than classic airspaces, thus, corridors-in-the-sky may increase national airspace capacity and reduce flight delays. To design corridors-in-the-sky, besides identifying their locations, their utilization, altitudes, and impacts on remaining system need to be analyzed. This paper chooses one tube candidate and presents analyses of spatial and temporal utilization of the tube, the impact on the remaining traffic, and the potential benefit caused by off-loading the traffic from underlying sectors. Fundamental issues regarding to the benefits have been also clarified. Methods developed to assist the analysis are described. Analysis results suggest dynamic tubes in terms of varied utilizations during different time periods. And it is found that combined lane options would be a good choice to lower the impact on non-tube users. Finally, it shows significant reduction of peak aircraft count in underlying sectors with only one tube enabled

Dynamically Evolving Sectors for Convective Weather Impact

A new strategy for altering existing sector boundaries in response to blocking convective weather is presented. This method seeks to improve the reduced capacity of sectors directly affected by weather by moving boundaries in a direction that offers the greatest capacity improvement. The boundary deformations are shared by neighboring sectors within the region in a manner that preserves their shapes and sizes as much as possible. This reduces the controller workload involved with learning new sector designs. The algorithm that produces the altered sectors is based on a force-deflection mesh model that needs only nominal traffic patterns and the shape of the blocking weather for input. It does not require weather-affected traffic patterns that would have to be predicted by simulation. When compared to an existing optimal sector design method, the sectors produced by the new algorithm are more similar to the original sector shapes, resulting in sectors that may be more suitable for operational use because the change is not as drastic. Also, preliminary results show that this method produces sectors that can equitably distribute the workload of rerouted weather-affected traffic throughout the region where inclement weather is present. This is demonstrated by sector aircraft count distributions of simulated traffic in weather-affected regions

Dynamics of Air Transportation System Transition and Implications for ADS-B Equipage

The U.S. Air Transportation Systems faces substantial challenges in transforming to meet future demand. These challenges need to be understood and addressed in order to successfully meet future system needs. This paper uses a feedback model to describe the general system transition process and identify key issues in the dynamics of system transition, with particular emphasis on stakeholder cost-benefit dynamics and safety approval processes. Finally, in addition to identifying dynamics and barriers to change the paper proposes methods for enabling transition through the use of levers such as incentives, mandates, and infrastructure development. The implementation of ADS-B is studied as a pathfinding technology for planned Air Transportation System changes. The paper states that overcoming stakeholder barriers and ensuring efficient safety approval and certification process are the key enablers to the successful implementation of ADS-B.This work was supported by the FAA under the Joint University Program (JUP) [FAA95-G-017] and the National Center of Excellence for Aviation Operations Research (NEXTOR) [DTFA01-C-00030]

Interaction of Airspace Partitions and Traffic Flow Management Delay

To ensure that air traffic demand does not exceed airport and airspace capacities, traffic management restrictions, such as delaying aircraft on the ground, assigning them different routes and metering them in the airspace, are implemented. To reduce the delays resulting from these restrictions, revising the partitioning of airspace has been proposed to distribute capacity to yield a more efficient airspace configuration. The capacity of an airspace partition, commonly referred to as a sector, is limited by the number of flights that an air traffic controller can safely manage within the sector. Where viable, re-partitioning of the airspace distributes the flights over more efficient sectors and reduces individual sector demand. This increases the overall airspace efficiency, but requires additional resources in some sectors in terms of controllers and equipment, which is undesirable. This study examines the tradeoff of the number of sectors designed for a specified amount of traffic in a clear-weather day and the delays needed for accommodating the traffic demand. Results show that most of the delays are caused by airport arrival and departure capacity constraints. Some delays caused by airspace capacity constraints can be eliminated by re-partitioning the airspace. Analyses show that about 360 high-altitude sectors, which are approximately today s operational number of sectors of 373, are adequate for delays to be driven solely by airport capacity constraints for the current daily air traffic demand. For a marginal increase of 15 seconds of average delay, the number of sectors can be reduced to 283. In addition, simulations of traffic growths of 15% and 20% with forecasted airport capacities in the years 2018 and 2025 show that delays will continue to be governed by airport capacities. In clear-weather days, for small increases in traffic demand, increasing sector capacities will have almost no effect on delays

Evaluation of the Terminal Sequencing and Spacing System for Performance Based Navigation Arrivals

NASA has developed the Terminal Sequencing and Spacing (TSS) system, a suite of advanced arrival management technologies combining timebased scheduling and controller precision spacing tools. TSS is a ground-based controller automation tool that facilitates sequencing and merging arrivals that have both current standard ATC routes and terminal Performance-Based Navigation (PBN) routes, especially during highly congested demand periods. In collaboration with the FAA and MITRE's Center for Advanced Aviation System Development (CAASD), TSS system performance was evaluated in human-in-the-loop (HITL) simulations with currently active controllers as participants. Traffic scenarios had mixed Area Navigation (RNAV) and Required Navigation Performance (RNP) equipage, where the more advanced RNP-equipped aircraft had preferential treatment with a shorter approach option. Simulation results indicate the TSS system achieved benefits by enabling PBN, while maintaining high throughput rates-10% above baseline demand levels. Flight path predictability improved, where path deviation was reduced by 2 NM on average and variance in the downwind leg length was 75% less. Arrivals flew more fuel-efficient descents for longer, spending an average of 39 seconds less in step-down level altitude segments. Self-reported controller workload was reduced, with statistically significant differences at the p less than 0.01 level. The RNP-equipped arrivals were also able to more frequently capitalize on the benefits of being "Best-Equipped, Best- Served" (BEBS), where less vectoring was needed and nearly all RNP approaches were conducted without interruption

Towards facades as Make-To-Order products – the role of Knowledge-Based-Engineering to support design

Building façades are Engineer-To-Order (ETO) products and, as such, they show unique features on a project-by-project basis. The partitioning of design tasks during the design and manufacturing process of these products, however, does not fully capture how specific design decisions influence other stakeholders’ choices. This lack of design integration is most severe at early stages when a large proportion of initial costs, mostly driven by manufacturability aspects, is determined. This paper illustrates a methodology to build Knowledge-Based Engineering (KBE) applications to support early-stage design integration through the development of a façade Product Model for automatic rule checking and knowledge reuse. The main outcome is a preliminary framework for developing knowledge-based, digital tools to support and integrate façade design as well as different scenarios in which the tool can potentially be used, based on two types of procurement methods. A prototype of the tool is also shown here. The paper proposes a new paradigm where façade systems are considered to be more closely related to Make-To-Order types, rather than ETOs, in which the product is ready for fabrication and designers can rapidly explore the subcontractor’s manufacturing capabilities and the implications of their design choices. Future work will include tool validation by applying the tool into a specific façade manufacturer’s workflow