Arrival Routes Research Articles

Revised approach procedures to support optimal descents into Malta International Airport

This paper presents a proposal for new approach procedures for the most commonly used runways at Malta International Airport, runways 31 and 13, as a basis to facilitate the introduction of optimal descents in Maltese airspace. In addition, a standard arrival, one from the north from where the large majority of aircraft approach Malta, linking to runway 31 is proposed. The design, following ICAO recommendations, is described in detail. Current practice of aircraft inbound from the same entry point, observed using ADS-B recorded data, is also presented in a discussion leading to the identification of gains that could result from flying the proposed arrival and approach routes optimally.

Optimization of Area Navigation Arrival Routes for Cumulative Noise Exposure

This paper presents a study aimed at the development of an optimization methodology for multi-event aircraft trajectories. The proposed methodology is an extension of the NOISHHH tool originally developed for the optimization of single-event trajectories. The new optimization framework has been developed to synthesize multi-event area navigation trajectories that minimize the community noise impact in near-airport communities due to the aggregated noise impact on near-airport communities of all inbound and outbound flights on a representative day. The methodology has been applied to nightly inbound flights at a large international airport, revealing a significant improvement of the community noise impact in terms of the number of people highly annoyed due to aircraft noise.

El Flamenco Americano (Phoenicopterus ruber) en la Orinoquia Colombiana: ¿Ampliación de Rango o introducción de Especie?

Titulo en ingles: The American flamingo (Phoenicopterus ruber) in the Colombian Orinoco region: extending its range or the introduction of the species?Titulo en portugues: Flamingo-americano (Phoenicopterus ruber) na Orinoquía colombiana: ampliação da sua distribuição geográfica ou introdução da espécie?Resumen: Se presentan los primeros registros del flamenco americano (Phoenicopterus ruber) para el piedemonte del departamento del Meta en la Orinoquia Colombiana. Se realizaron tres observaciones en vida silvestre de la especie en las zonas inundadas de un cultivo de arroz de riego (Oryza sativa) en los años 2008 y 2010. Estos registros podrían corresponder a la ampliación de rango de la especie, a la presencia de individuos vagabundos o a la introducción tipo trasplante de la especie a esta región del país. Se analizó la situación de P. ruber en la Orinoquia Colombiana, se proponen las posibles rutas de arribo de la especie a esta región del país (si fuese una ampliación de rango geográfico) y se discuten la tenencia de fauna silvestre en cautiverio.Palabras clave: Llanos orientales, introducción, tráfico ilegal fauna, arrozales, Oryza sativa.Abstract: The first sightings of the American or Caribbean flamingo (Phoenicopterus ruber) in the foothills of the Meta department in the Colombian Orinoco region are presented here. Three observations of the species were made in the wild in the flooded areas of an irrigated rice (Oryza sativa) paddy from 2008 to 2010. These records could show how the species' range is becoming extended, the presence of individual vagrants or the specie's transplant-type introduction into this region of Colombia. The circunstances regarding P. ruber 's presence in the Colombian Orinoco region is analysed, possible arrival routes for the species to this region of Colombia are proposed (if one is dealing with an expansion of geographical range) and captive wildlife occupancy are discussed.Key words: Colombian Eastern plains, introduction, illegal wildlife trade, rice paddy, Oryza sativa.Resumo: O trabalho apresenta os primeiros registros do Flamingo-americano (Phoenicopterus ruber) para a região da base da montanha, do departamento de Meta em Orinoquia Colombiana. Foram realizadas três observações sobre a vida silvestre desta espécie em regiões com cultivo de arroz alagado (Oryza sativa) durante os anos de 2008 e 2010. Esses registros demonstram o crescente leque de espécies, e a presença de indivíduos que perderam ás áreas para sobreviver, representando a transposição desta espécie para esta área do país. A situação analisada em P. Ruber na Orinoquia Colombiana propõe a existência de possíveis rotas que permitem a chegada desta espécie a essa região, e discutem as implicações da tendência de manutenção da fauna silvestre em cativeiro.Palavras chave: planícies do leste, introdução, tráfico de animais selvagens, arroz, Oryza sativa.

Separation-compliant, optimal routing and control of scheduled arrivals in a terminal airspace

We address the problem of navigating a set (fleet) of aircraft in an aerial route network so as to bring each aircraft to its destination at a specified time and with minimal distance separation assured between all aircraft at all times. The speed range, initial position, required destination, and required time of arrival at destination for each aircraft are assumed provided.Each aircraft’s movement is governed by a controlled differential equation (state equation). The problem consists in choosing for each aircraft a path in the route network and a control strategy so as to meet the constraints and reach the destination at the required time. The main contribution of the paper is a model that allows to recast this problem as a decoupled collection of problems in classical optimal control and is easily generalized to the case when inertia cannot be neglected. Some qualitative insight into solution behavior is obtained using the Pontryagin Maximum Principle. Sample numerical solutions are computed using a numerical optimal control solver.The proposed model is first step toward increasing the fidelity of continuous-time control models of air traffic in a terminal airspace. The Pontryagin Maximum Principle implies the polygonal shape of those portions of the state trajectories away from those states in which one or more aircraft pair are at minimal separation. The model also confirms the intuition that, the narrower the allowed speed ranges of the aircraft, the smaller the space of optimal solutions, and that an instance of the optimal control problem may not have a solution at all (i.e., no control strategy that meets the separation requirement and other constraints).

Benefits of Precision Scheduling and Spacing for Arrival Operations

Advances in arrival scheduling and controller aids for spacing have the potential benefits of reducing aircraft delays and increasing airport arrival throughput. Schedulers use fixed arrival paths to estimate aircraft’s time-to-fly and assign them arrival slots based on the required separation with a buffer. Concepts that reduce arrival time uncertainty can take advantage of advanced scheduling with smaller spacing buffers. These concepts have been successfully demonstrated with a handful of near- to midterm traffic demand scenarios and technologies using spacing buffers as low as 0.3 n mile. The analysis published here characterizes the observed arrival spacing behavior of 29 runways at 15 airports in eight of the busiest terminal areas across the United States during 32–60 days worth of traffic. The typical observed instrument arrival buffers ranging from 0.5 to 1.5 n mile would equate to roughly a 10–20% increase in runway arrival capacity if buffers were reduced to 0.3 n mile. The effect of fixed arrival routing on terminal area flight time was also studied. Most runways studied had a significant path stretch delay. This work estimates that 1–2 min of this delay could be reduced with precision scheduling, and most of the remaining delay could be absorbed by speed control.

Minimum time-dependent travel times with contraction hierarchies

Time-dependent road networks are represented as weighted graphs, where the weight of an edge depends on the time one passes through that edge. This way, we can model periodic congestions during rush hour and similar effects. In this work we deal with the special case where edge weights are time-dependent travel times. Namely, we consider two problems in this setting: Earliest arrival queries ask for a minimum travel time route for a start and a destination depending on a given departure time. Travel time profile queries ask for the travel time profile for a start, a destination, and an interval of possible departure times. For an instance representing the German road network, for example, we can answer earliest arrival queries in less than 1.5ms. For travel time profile queries, which are much harder to answer, we need less than 40ms if the interval of possible departure times has a width of 24 hours. For inexact travel time profiles with an allowed error of about 1% this even reduces to 3.2ms. The underlying hierarchical representations of the road network, which are variants of a time-dependent contraction hierarchy (TCH), need less than 1GiB of space and can be generated in about 30 minutes. As far as we know, TCHs are currently the only method being able to answer travel time profile queries efficiently. Altogether, with TCHs, web servers with massive request traffic are able to provide fast time-dependent earliest arrival route planning and computation of travel time profiles.

Modelling of material handling systems for facility design in manufacturing environments with job-specific routing

Traditionally, flow times distance is used as a surrogate for cost in facility design. However, this performance measure does not fully capture the impact of facility design decisions on operational performance measures such as cycle time and work-in-progress in the system, which are often more meaningful for managers, especially in a manufacturing environment. To better measure operational performance, modelling of material handling systems using a queueing network must be integrated in the facility design process. A number of approaches are discussed in the facility design literature for modelling material flow using queueing networks. In these approaches, Poisson arrival or Markovian job routing assumptions have been used. However, for many manufacturing environments, these assumptions lead to an inaccurate estimation of the material handling system's performance and thus lead to poor facility designs. Incorporating more general queueing results for non-Markovian systems is difficult, however, because the facility design process must investigate a large number of potential solutions and thus the results from the queueing models for the material handling system must be quickly obtained. In this paper, the need for more general queueing models of material handling systems in facility design is confirmed. Then, an approach based on multi-class queueing models is adapted to capture the change in variability of the system performance caused by both different arrangements of workstations in the facility and different arrival processes to the workstations due to the job routing in a computationally efficient manner. The proposed modelling approach is shown to provide more accurate results than previous methods used in facility design based on numerical comparisons with results from discrete-event simulation.

A Medium Term Conflict Detection and Resolution system for Terminal Maneuvering Area based on Spatial Data Structures and 4D Trajectories

In this paper an efficient Medium Term Conflict Detection and Resolution (MTCD&R) approach based on 4D trajectories to solve conflicts in a Terminal Maneuvering Area (TMA) is presented. The conflict detection subsystem (CD) is based on a Spatial Data Structure (SDS), avoiding non-efficient pairwise trajectory comparisons, and using a simplified wake vortex modeling through 4D tubes to detect time-based separation infringements between aircraft. The conflict resolution subsystem (CR) solves the detected conflicts with an efficient and dynamic 3D allocation of the arrival routes that takes into consideration the execution of Continuous Descent Approaches (CDAs). Algorithms have been tested with several stressing traffic scenarios (rush hour and saturation rush hour) taking place in a 3D simulation model of Gran Canaria Extended TMA. The resulting conflict-free trajectories have been validated for flyability conformance both with real A380 FMS avionics and with a certified B738 Full Flight Simulator. A new CR performance metric to measure the degree of runway utilization is also proposed in order to enable comparisons between different MTCD&R systems. Finally, a discussion about strengths and limitations of the algorithms for reducing controller’s workload while increasing airspace capacity of the future Single European Sky is outlined.

Analytical modeling of a multi-queue nodes network router

This paper presents the derivation of an analytical model for a multi-queue nodes network router, which is referred to as the multi-queue nodes (mQN) model. In this model, expressions are derived to calculate two performance metrics, namely, the queue node and system utilization factors. In order to demonstrate the flexibility and effectiveness of the mQN model in analyzing the performance of an mQN network router, two scenarios are performed. These scenarios investigated the variation of queue nodes and system utilization factors against queue nodes dropping probability for various system sizes and packets arrival routing probabilities. The performed scenarios demonstrated that the mQN analytical model is more flexible and effective when compared with experimental tests and computer simulations in assessing the performance of an mQN network router.

Embedded Statistical Analysis and Selection Procedures in Air Traffic Simulations

Statistical analysis and adaptive sampling techniques can be embedded within existing air traffic simulations to provide several benefits. First, embedded statistical calculations can eliminate the need for extensive storage and post hoc processing of simulated outputs. Second, adaptive sampling can identify the number of observations required for rigorous statistical comparison, often dramatically reducing the number and duration of simulation runs from those predicted a priori by standard statistical techniques, which tend to be quite conservative. Third, these methods facilitate efficient distribution of simulator runs over a network of workstations without requiring parallelization of the simulation software.This paper describes three central components required for these benefits: (1) embedded statistical calculations; (2) adaptive statistical selection techniques; and (3) the server-client structure for a network of workstations in which individual workstations gather and report interim statistics and then are commanded to perform those further simulation runs required for a given statistical comparison. Their application to air traffic simulation is demonstrated using the Georgia Tech Reconfigurable Flight Simulator in a simulation of a standard terminal arrival route into Atlanta Hartsfield-Jackson airport in which the appropriate simulation runs were automatically carried out until the ‘best’ (or ‘worst’) systems were identified.

Reducing Fuel Consumption in Bucharest Terminal Area for Flights Using a Standard Instrument Departure

Reconfiguration of the standard instrument departure and standard arrival routes at certain airports can bring significant reductions in fuel consumption and level of noise. This can be done either by implementing modern radionavigation aids for terminal areas or by eliminating the flying restrictions over cities and inhabited places and designing of low level of noise procedures for these areas. These solutions have other important benefits like decreasing the workload for the air traffic controllers and reducing the total flight time. The paper describes an operational solution in this manner for Bucharest Henri Coanda International Airport.

Tactical Conflict Detection in Terminal Airspace

Air traffic systems have long relied on automated short-term conflict prediction algorithms to warn controllers of impending conflicts (losses of separation). The complexity of terminal airspace has proven difficult for such systems as it often leads to excessive false alerts. Thus, the legacy system, called Conflict Alert, which provides short-term alerts in both en-route and terminal airspace currently, is often inhibited or degraded in areas where frequent false alerts occur, even though the alerts are provided only when an aircraft is in dangerous proximity of other aircraft. This research investigates how a minimal level of flight intent information may be used to improve short-term conflict detection in terminal airspace such that it can be used by the controller to maintain legal aircraft separation. The flight intent information includes a site-specific nominal arrival route and inferred altitude clearances in addition to the flight plan that includes the RNAV (Area Navigation) departure route. A new tactical conflict detection algorithm is proposed, which uses a single analytic trajectory, determined by the flight intent and the current state information of the aircraft, and includes a complex set of current, dynamic separation standards for terminal airspace to define losses of separation. The new algorithm is compared with an algorithm that imitates a known en-route algorithm and another that imitates Conflict Alert by analysis of false-alert rate and alert lead time with recent real-world data of arrival and departure operations and a large set of operational error cases from Dallas/Fort Worth TRACON (Terminal Radar Approach Control). The new algorithm yielded a false-alert rate of two per hour and an average alert lead time of 38 seconds.

RNAV平行経路の最小経路間隔の一推定方法

An area navigation (RNAV) road map was prepared by the Japan Civil Aviation Bureau for effective aircraft operation and effective utilization of air space. Following the road map, RNAV routes have been implemented in Japan. RNAV is a method of navigation which permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self-contained aids, or a combination of these. This paper describes a methodology for estimating safe minimum route spacing for RNAV-approved aircraft. Radar track data of aircraft which flew on a Kagoshima RNAV standard terminal arrival route (STAR) were collected for six months for the purpose of analyzing the cross-track deviations for RNAV-approved aircraft. The distribution of cross-track deviations was estimated using this data set. A probability distribution model of it was then found. The lateral overlap probability was estimated using the empirical distribution and its deformation. Collision risk was estimated using the estimate of lateral overlap probability together with other given parameters. Comparing the estimated collision risk with the target level of safety (TLS) for the lateral dimension separation minimum, safe minimum route spacing was obtained. As a result, in the case that the population of aircraft with poor navigation performance, i.e., barely meeting the 95% containment requirement for RNAV approved aircraft, is assumed to be 10 percent, estimates of safe minimum route spacing are 8 nautical miles (NM) for RNAV1-approved aircraft and 32NM for RNAV5-approved aircraft, respectively. Additionally, safe minimum route spacing which takes into account of the fluctuation of data is estimated using the Bootstrap method. The result shows that the estimated ranges of minimum route spacing are 7NM-9NM for RNAV1-approved aircraft and 29NM-38NM for RNAV5-approved aircraft, respectively.

Optimal Dynamic Scheduling of Aircraft Arrivals atCongested Airports

An optimal airport arrival scheduling algorithm, which works within a hierarchical scheduling structure, is presented. This structure consists of schedulers at multiple points along the arrival route. Schedulers are linked through acceptance rate constraints, which are passed up from downstream metering points. The innovation in this algorithm is that these constraints are computed by using an Eulerian model-based optimization scheme. In this scheme an aggregate airspace model is derived online. Optimization based on predictions of this model is used to compute the optimal acceptance rates at all metering points, so that the airport throughput is maximized while keeping sector counts within limits. This rate computation removes inefficiencies introduced in the schedule through ad hoc acceptance rate computations. The scheduling process at every metering point uses its optimal acceptance rate as a constraint and computes optimal arrival sequences by using a combinatorial search algorithm. We test this algorithm in a dynamic air-traffic environment, which can be customized to emulate different arrival scenarios. Results from Monte Carlo simulations show improved performance over first-come, first-served ordering for different values of key parameters such as arrival aircraft mix, average arrival rate, maximum position-shift constraint, and level of uncertainty in estimated time of arrival prediction.

11612 RNAV到着経路を飛行する航空機の横方向経路逸脱量の分布の推定(各種システムの安全性(2),OS.10 各種システムの安全性)

11612 RNAV到着経路を飛行する航空機の横方向経路逸脱量の分布の推定(各種システムの安全性(2),OS.10 各種システムの安全性)

Automated Route Generation for Avoiding Deterministic Weather in Transition Airspace

We investigate the problem of synthesizing weather avoidance routes in the transition airspace, from the 200 n mile range to the metering fixes of an airport, given a deterministic weather forecast. The investigation of the problem is motivated by the desire to maximize airspace capacity while ensuring safe separation between aircraft and between aircraft and hazardous weather. Three solution methods are compared with current day operations. Emphasis is placed on a comparison of the arrival traffic weather avoidance routing method and metrics associated with such routes. Historical weather avoidance paths (baseline) are compared with three alternatives: variations of the standard arrival routes, a geometric optimization solution synthesizing multiple nonintersecting routes, and two free-flight approaches in which aircraft fly weather avoidance routes using a greedy prioritization method. Results indicate that increases in capacity over today's system are achievable, while maintaining safety. However, such increases are limited by the method, the required supporting infrastructure, and weather severity and location.

RNAV到着機の横方向経路逸脱量の推定

For effective aircraft operation, Civil Aviation Bureau promotes route restructuring for utilizing Area Navigation (RNAV) operation by means of making an RNAV roadmap. RNAV is a method of navigation which permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self-contained aids, or a combination of these. Estimating optimal route spacing between parallel arrival routes is required. It's necessary to estimate lateral overlap probability, which is one of the most important parameters of collision risk model, for estimating the risk of the given route spacing. For estimating the lateral overlap probability, a distribution of cross track deviations was estimated using the radar data of Kagoshima Airport, flight plan data and flight strips. The results obtained are as follows. (1) The standard deviation of the observed cross track deviations of 2,298 flights is 0.077 NM. (2) The ninety five percent containment interval of the deviations is [-0.13 NM, 0.17 NM]. (3) The best fitted model for the empirical cross track deviations is the mixed model of two Normal (Gaussian) distributions. The fitted parameters are α=0.117, σ_1=0.0673 NM and σ_2=0.129 NM.

Odyssey of stow-away noctuid moths to southern polar islands

High southern latitude island environments are unusual in having relatively low or, in some cases, no non-indigenous species (NIS). Here we describe the accidental transport and survivorship of moths (Lepidoptera, Noctuidae) on a research vessel travelling from southern South America (Montevideo, Uruguay) first to the cool temperate Falkland Islands and then onwards to Maritime Antarctic Signy Island (South Orkney Islands). On the vessel's arrival at Stanley, Falkland Islands, from Montevideo we found eight live (and 30 dead) individuals of two species of South American noctuid moth (Pseudaletia adultera Schaus and Peridroma saucia (Hübner)), presumed to have been attracted to the ship's lights while in port. Neither of these is indigenous to the Falkland Islands. Five of the eight living moths (all P. adultera) survived the four days the ship was moored in Stanley and one survived a further four day journey across the Polar Front to Signy Island. Southern oceanic islands are particularly vulnerable to invasion by NIS, with human (shipping) activities being the main route of arrival. With increasing shipping throughout this region some measures have been proposed or adopted to reduce the risk of NIS transfer.

Pilot-Performed In-Trail Spacing and Merging: An Experimental Study

Responsibility for the guidance of aircraft in the National Airspace System is currently given largely to the air traffic controller. This study investigated the benefits of having pilots more involved in guidance during two representative air traffic management operations: maintaining in-trail separation and arrival sequencing. This included 12 airline pilots flying arrival routes in a part-task, medium-fidelity simulator, during which they were responsible for attaining and maintaining a commanded relative position within the traffic flow. A variety of cockpit displays of traffic information and procedures were tested, and the pilots' performance was tracked during both nominal and off-nominal traffic situations. Results provide preliminary evidence of the benefit of pilot involvement in the guidance component of these operations. Suggestions are given for modifications to cockpit avionics systems. The need for established air traffic control procedures to provide foreknowledge to the pilots and a structure within which pilots can interact is also highlighted, illustrating that improvements to aircraft guidance within the National Airspace System may benefit from both technical and procedural changes.

A dated pollen record of vegetation change on Mayor Island (Tuhua) throughout the last 3000 years

Pollen data are presented from Mayor Island, Bay of Plenty. The island was important in prehistory as a source of obsidian (Seelenfreund, A., Bollong, C., 1989. The sourcing of New Zealand obsidian artefacts using energy dispersive XRF Spectroscopy. In: D. Sutton (Editor), Saying So Doesn't Make It So: Papers in honour of B. Foss Leach. New Zealand Archaeological Association Monograph, Wellington, pp. 168–189.) and holds a strategic location relative to the settlement of the North Island of New Zealand since it lies on possible arrival routes from Polynesia, and also relative to travel up and down the east coast of the North Island. The pollen data show that the island was generally forested between c. 3000 and c. 450 BP, when forest declined and the bracken fern Pteridium esculentum (and charcoal) increased. Before significant forest decline at 450 BP, which is consistent with Maori occupation at the time of the fortified settlements known as pa, there is evidence of other episodes of vegetation disturbance dating back to c. 2200 BP which may represent earlier visits by people.