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Most of the existing approaches for flight collision avoidance are concerned with local traffic alone for which the separation is based on the pairwise analysis of aircraft trajectory trends, which is not efficient with regard to some flight path requirements along waypoints. The purpose of this paper is to deal with the global collision avoidance problem which aims at separating aircraft taking into consideration the global traffic in a given area instead of considering them pairwise. It aims to model the concept of global collision avoidance and propose a validated algorithm for the purpose in the framework of free‐flight.

The collision avoidance procedure computes online the appropriate speed and heading for each aircraft, at each sampling time‐instant, to generate a collision‐free flight trajectory along scheduled waypoints. The method accounts for automatic assignment of priority indexes that are updated from one control time horizon to the next. The paper considers here the case of aircraft flying at the same altitude, but the proposed method is easily extendable to the general 3D situation. Owing to the predictive features that are inherent to collision avoidance, the collision‐free trajectories are generated using model predictive control approach. A simulation example is presented in the end and its results show the suitability of the proposed approach.

Since the model predictive control approach is used, the collision avoidance procedure is anticipative; therefore, the avoidance capability depends only on the prediction horizon rather than on the control horizon.

The computation of the trajectory guidance information (speed and heading) at each time‐step is fast, therefore the proposed method is well suited for online processing requirements in real world applications.

The paper provides a flexible modelling framework and a computationally effective algorithm, both based on model predictive control concepts, to cope with global collision avoidance for flight safety enhancement in the framework of free‐flight.

Purpose – To examine the relationship between aviation and climate change, and the international dimensions of air transport.

Methodology/approach – A review of aviation's impacts on the global climate, mitigation strategies to reduce this impact, and the possible consequences of climate change for commercial aviation.

Findings – Although a range of mitigation measures have been developed and implemented to reduce aircraft emissions in the short term, with some environmental benefit, there is a real need for the aviation sector to identify the possible impacts of climate change on air travel operations, both to aircraft in flight and to operations at airports. A further challenge will be to devise adaptation plans that will address the vulnerabilities and thus ensure safe aviation-related operations.

Social implications – The climate change impacts of aviation will adversely affect society. In addition, some individuals may have to reduce or stop flying as a result of increased taxes and legislation implemented in response to climate change.

Originality/value of paper – There is a novel focus on the adaptation challenges for the aviation industry in response to climate change.

The purpose of this paper is to calculate the probability of collision of flying aircraft crossing on straight paths in any direction.

The probability of deviations from the intended flight paths is used to calculate the probability of collision that is integrated over time to cover whole events.

The probabilities of collision are calculated in terms of the r.m.s. position errors and encounter geometry, that is aircraft velocities and flight path angles and crossing angles.

The method does not apply to aircraft flying in parallel tracks at the same velocity in air corridors: that case has been covered elsewhere, as well as the case of climbing or descending aircraft.

International Civil Aviation Organization (ICAO) specifies as target level of safety (TLS) a probability of collision not exceeding 5×10⁻⁹ per hour. To meet the ICAO TLS standard, it is necessary to calculate collision probabilities for all stages of flight.

A low collision probability is a safety metric; the value does depend on a realist choice of probability distribution.

Calculates the probability of collision for crossing flights, corresponding to a common scenario on air traffic management.

Alcoa will again be present at the Paris Air Show. Its Stand will be featuring the latest materials technologies and product capabilities. Alcoa technical specialists and senior executives will be on hand to present and discuss the progress which has been made since the last Air Show.