Beyond Contrail Avoidance: Efficacy of Flight Altitude Changes to Minimise Contrail Climate Forcing

Contrail cirrus introduce a short-lived but significant climate forcing that could be mitigated by small changes in aircraft cruising altitudes. This paper extends a recent study to evaluate the efficacy of several vertical flight diversion strategies to mitigate contrail climate forcing, and estimates impacts to air traffic management (ATM). We use six one-week periods of flight track data in the airspace above Japan (between May 2012 and March 2013), and simulate contrails using the contrail cirrus prediction model (CoCiP). Previous studies have predominantly optimised a diversion of every contrail-forming flight to minimise its formation or radiative forcing. However, our results show that these strategies produce a suboptimal outcome because most contrails have a short lifetime, and some have a cooling effect. Instead, a strategy that reroutes 15.3% of flights to avoid long-lived warming contrails, while allowing for cooling contrails, reduces the contrail energy forcing (EFcontrail) by 105% [91.8, 125%] with a total fuel penalty of 0.70% [0.66, 0.73%]. A minimum EFtotal strategy (contrails + CO2), diverting 20.1% of flights, reduces the EFcontrail by the same magnitude but also reduces the total fuel consumption by 0.40% [0.31, 0.47%]. For the diversion strategies explored, between 9% and 14% of diversions lead to a loss of separation standards between flights, demonstrating a modest scale of ATM impacts. These results show that small changes in flight altitudes are an opportunity for aviation to significantly and rapidly reduce its effect on the climate.

Identification of Aircraft Wake Vortex Based on SVM

The aircraft wake vortex has important influence on the operation of the airspace utilization ratio. Particularly, the identification of aircraft wake vortex using the pulsed Doppler lidar characteristics provides a new knowledge of wake turbulence separation standards. This paper develops an efficient pattern recognition-based method for identifying the aircraft wake vortex measured with the pulsed Doppler lidar. The proposed method is outlined in two stages. (i) First, a classification model based on support vector machine (SVM) is introduced to extract the radial velocity features in the wind fields by combining the environmental parameters. (ii) Then, grid search and cross-validation based on soft margin SVM with kernel tricks are employed to identify the aircraft wake vortex, using the test dataset. The dataset includes wake vortices of various aircrafts collected at the Chengdu Shuangliu International Airport from Aug 16, 2018, to Oct 10, 2018. The experimental results on dataset show that the proposed method can identify the aircraft wake vortex with only a small loss, which ensures the satisfactory robustness in detection performance.

U-Space Concept of Operations: A Key Enabler for Opening Airspace to Emerging Low-Altitude Operations

Opening the sky to new classes of airspace user is a political and economic imperative for the European Union. Drone industries have a significant potential for economical growth according to the latest estimations. To enable this growth safely and efficiently, the CORUS project has developed a concept of operations for drones flying in Europe in very low-level airspace, which they have to share that space with manned aviation, and quite soon with urban air mobility aircraft as well. U-space services and the development of smart, automated, interoperable, and sustainable traffic management solutions are presented as the key enabler for achieving this high level of integration. In this paper, we present the U-space concept of operations (ConOps), produced around three new types of airspace volume, called X, Y, and Z, and the relevant U-space services that will need to be supplied in each of these. The paper also describes the reference high-level U-space architecture using the European air traffic management architecture methodology. Finally, the paper proposes the basis for the aircraft separation standards applicable by each volume, to be used by the conflict detection and resolution services of U-space.

УТОЧНЕНА МЕТОДОЛОГІЯ ПРОАКТИВНОЇ ІНТЕГРАТИВНОЇ ОЦІНКИ СТАВЛЕННЯ АВІАДИСПЕТЧЕРІВ ДО ПОРУШЕНЬ СТАНДАРТНИХ ЕКСПЛУАТАЦІЙНИХ ПРОЦЕДУР

Representing the professional activities of the «front-line» aviation operators as an unbroken chain of decisions made and implemented in explicit/implicit forms, the interaction of the components of the current paradigm of the ICAO flight safety concept is placed on “the attitude of aviation personnel to hazardous actions or conditions”, which explains the impact human factor in these decisions. The first part of the studied “attitude” is the main decision-making dominants that determine preposition, indifference, and aversion to risk of violations of standard operating procedures, in particular, aircraft separation standards. Dominants are established by constructing a finite number of points and further analyzing the utility function of the continuum of the separation rate in the process of solving a closed decision problem. A characteristic point of the estimated utility function is the deterministic equivalent of the lottery with a benefit of 0.75. The second component is the level of claims, which are determined by a point on the continuum of the separation norm, which corresponds to the maximum positive leap in the imagination of the air traffic controller in terms of its usefulness (acceptability) from the standpoint of ensuring the proper level of flight safety. The levels of claims adequately characterize self-esteem and are established by constructing a formally unlimited number of points and further analysis of the estimation function of the continuum of the separation norms in the process of solving open decision-making problems. The third component - fuzzy risk assessments, which are determined from the analysis of fuzzy models, are built in accordance with the ICAO scale of hazards on a continuum of separation standards. It has been established that a characteristic point of these models is the intersection point of membership functions belonging to the neighboring terms “significant” and “insignificant” risk. The value of this point is specified using the introduced imperative - criterion. Normalization of all characteristic points has been carried out. The multiplicative approach to obtaining an integrative (holistic) assessment of the attitude towards risk is substantiated and implemented, which contributes both to obtaining a more cautious, relatively additive approach to the results, and to prevent errors of the I-II kind.

ПРОАКТИВНЕ ВИЗНАЧЕННЯ ВПЛИВУ ДОСВІДУ УПРАВЛІННЯ ПОВІТРЯНИМ РУХОМ НА СТАВЛЕННЯ ДО РИЗИКУ

Considering the long negative influence of the human factor on flight safety, ICAO has been orienting the leadership and specialists of state aviation administrations and airlines to the proactive prevention of this phenomenon, demanding flight safety effective management "by indicators". These indicators in terms of professional activity of air traffic controllers (ATC) are defined: the relation to the risk (the main decision-makers and controversial estimates of SOP's violations), levels of claims, preferences systems, and dangerous behavior strategies, operational thinking and decision making that, in contrast to formally computational methods reflect the implementation of the methodology of psychological decision theory and cognitive psychology. The main decision-making dominants (inclination, disinclination, and indifference to risk) are revealed in the process of proactive decision by the controllers of closed decision-making tasks by constructing, with the help of special artificial lotteries and a limited number of points, the utility functions of the continuity of aircraft separation standards in the horizontal plane. For the separation standard S = 20 km, the proportion of students-controllers (n = 128 persons) of inclined (INC), indifferent (IND) and disinclined to risk (D) was detected: INC:IND: D ↔ 5: 18: 105 ↔ 3.9%: 14.1%: 82.0% ↔ 1: 3.6: 21, which indicates their desire to avoid failures in their professional activities. Therefore, the quantitative indicator of demonstrated risk aversion increases with the complication of the separation standard (reducing the distance between aircraft). For the separation level S = 10 km it is established: INC:IND: D ↔ 5: 8: 115 ↔ 3.9%: 6.3%: 89.8% ↔1: 3.6: 21. In professional controllers (n = 70 persons), for the separation standard S = 20 km, the ratio of persons with different dominance of decision-making was found: IND: INC ↔ 9: 25: 36 ↔ 12.9%: 35.7%: 51.4 % ↔1: 2.8 : 4, which indicates an overwhelming demonstration of their motivation to achieve success in the same working conditions. The motivation increases with the complexity of the separation standard: for S = 10 km it is established: D: IND: INC ↔ 4: 18: 48 ↔ 5.7%: 25.7%: 68.6% ↔ 1: 4.5: 12. It is recommended to apply the obtained results during the organization of the person-oriented training of young dispatchers aiming at developing stable skills for making rational risk decisions.

The system of collaborative decision making as an effective tool for the organization of the airport operation in peak loads

In the article the analysis of functioning a joint decision-making (A-CDM) system of Sheremetyevo Airport is presented during airport operation in a "rush hour". Domestic and international programs of air traffic management (ATM) development assume that the airports will be completely included into the air traffic management network as components of this network. Cooperative decision-making will be used to provide a "seamless" process of planning. This process will take place with participation of airspace users, suppliers of an air navigation service and airports (with use of the automated facilities of arrival, departure and traffic on airfield surface) for the benefit of sequence management to increase runway capacity. The runway equipment has to be modernized, separation standards among aircraft on arrival and departure should be reduced, modern navigation and traffic control on an airfield surface aids have to operate. The runway is referred to the resources which operate according to the principle of only one client service. Influence of weather conditions (the wet runway, severe wind, low visibility) determines the airfield capacity. Arrival and departure control allows optimizing aerodrome operation from the view of cost efficiency and ecology. The system of joint decision-making for an airport is a complex of the procedures aimed at increasing level of air traffic flows organization, airfield and airspace capacity through raising a level of event predictability and optimization of the resource use process. The system allows operating information to obtain the modified output data for decision-making. The main system objectives are to increase the level of temporary accuracy of an event emergence and also its predictability.