The negative impact of air incidents and emergency situations results from the leakage of liquids into the soil and water and the leakage of flue gases and combustion products of aircraft structural materials into the air during fires. This article deals with air pollution caused by the combustion of composite materials commonly used in general aviation. Samples of composite materials of aircraft registered in the Czech Republic were selected. These samples of composite materials were tested for flammability, according to ISO 5660-1:2002 Reaction to fire tests—Heat Release, smoke production and mass loss rate (ISO—International Organization for Standardization). Total smoke release and total oxygen consumed were assessed in this study, both of which have a significant impact on air quality in the case of an air incident. Based on the results of the research, differences resulting from the diversity of the structures of the tested composite materials were found. The most hazardous composite material was evaluated from the point of view of its impact on air quality during combustion.

Accurate navigation systems allow us to optimize the trajectory of flying objects and thus solve environmental problems in aviation and their impact on public health. In this paper, we present one of the methods of assessment of accuracy and resistance to interference of distance-measuring equipment (DME). By using computer technology, the method enables us to determine the potential but also the real error measuring the distance of the flying object from DME. The credibility of the respective results of the solution on the task of DME optimal rangefinder synthesis depends on the accuracy of the previous data used, i.e., mathematical models of the respective flying objects flight dynamics, useful signals, and their parameters and interference. DME systems have an impact on air transport safety, and therefore the impact of interference on their operation must be investigated.

Within the new air traffic management concept, using the Global Navigation Satellite System (GNSS), it is assumed that distance measurement equipment (DME) will be retained. The results of research carried out by several authors have confirmed that global navigation satellite systems (GNSS) can be put out of operation in cases of interference. Therefore, it is very timely to investigate the accuracy and resistance to interference of DME systems. The presented work contains the results of research in the field of assessment of the accuracy and resistance of a DME system, which works in conditions of narrowband interference, using modeling and simulation. Based on the derived model of the DME measurement signal, its parameters, and narrowband interference, algorithms for processing the measurement signals of a DME system in conditions of narrowband interference were derived. A quasi-optimal nonlinear filtering method was used in the derivation of the measurement signal-processing algorithms. A quadratic loss function was used as an optimality criterion, which allows us to obtain the results of measuring the parameters of the DME measurement signal as a minimum of the a posteriori mean error. Within this method, Gaussian approximation and large and small parameter methods were used. Simulation of the operation of the DME system confirmed that the measurement accuracy of this system depends on the stability of the frequency of the DME support generator, and also depends on the signal-to-noise ratio and the signal-to-interference ratio of the DME receiver input. Comparing the results of the DME system receiver designed by us with the parameters listed in in published works that discuss the accuracy of this system, we can conclude that its accuracy is much better. The simulation results confirmed that the potential accuracy of the distance measurement is equal to 2.2 m. However, the mentioned algorithms require substantial simplification to be used for real-time signal processing. This will be our next research direction.

This paper presents the results of the research in the field of anti-collision systems for small civil aircraft, which are not dependent on secondary radars and satellite navigation systems. The aviation communication network was used to design the anti-collision system. The simulation results manifested that the anti-collision system precision depended on the errors of synchronization of the aviation communication network. The precision of the anti-collision system is also influenced by the errors of the coordinates of individual aviation communication network users, based on which the system identifies its own position. The results of the simulation show that the dispersion of the positioning error σ²_∆P by the ACS system varied in the range of 1.94 m² to 503.23 m². The simulation results confirm that the designed anti-collision system is operational in establishing its position against other FOs, with the distance from the given FOs being 50.0 km maximum. The main contribution of this paper are derived algorithms for the operation of an anti-collision system for small civil aircraft, in addition to the design of movement trajectory models of five flying objects which operate within the aviation communication network. The advantage of the anti-collision system is that it is independent of satnav systems and secondary radars. A significant advantage is the low cost of this system.

The quality of Galileo system services is affected by the accuracy of distance determination from the user’s application to the individual satellite. The goal of our research was to find out what influence the accuracy of distance determination between the user’s application of the Galileo system and the cooperating satellites of the Galileo system has on the ability to determine the location of the user’s application. A solution based on Groebner’s algebraic approaches was used to determine the receiver user’s position. When creating distance measurement error models between the Galileo system user’s receiver and cooperating satellites, we assumed that the values of those errors considered all factors that affected the accuracy of those distance measurements. To evaluate the algorithms, we used a statistical set of 500 simulation results to determine the positioning of the user’s application of the Galileo system. If the distances between the user’s application and the individual satellite were measured accurately, then the user’s application coordinate errors had values between 1.86 × 10⁻⁹ m and −1.8 × 10⁻⁸ m. These errors should be equal to zero. The positioning error was caused by a numerical error in the calculation due to the software used. If the errors of distance determination from the user’s application to the individual satellite varied from −0.05 m to 0.09 m, then the error in determining the positioning of the user’s application of the Galileo system was from 0.0 m to 1.2 m. If the distances of the user’s receiver to the satellites were measured with errors greater than 0.09 m, the errors in determining its position were much larger. The simulation results confirmed the known fact that the satellites’ geometry influences the accuracy of determining the location of the user’s application. In the following research, we will solve the problem of how to reduce the sensitivity of the mentioned algorithms when determining the position of the satellite navigation system receiver due to errors in determining the distance from the user’s application to the individual satellite.

This paper created a flight trajectory model of five uncrewed aerial vehicles (UAVs) in the geocentric coordinate system, provided the UAVs fly in the specified formation. Based on this model, equations for determining the position of a selected member of a group of UAVs were created, provided that the group communicates with each other in its telecommunications network. The simulation confirmed that if we know the exact coordinates of the four member UAVs of the group and their distances from the leader of the group, then the mean value of the error in determining its position in flight is equal to 0.044 m, and the variance is equal to 2.9 m². We consider these errors to be methodological errors of the proposed method. Next, we checked how the error of determining the position of the group leader depends on the distance measurement errors between the individual UAVs and the group leader. The simulation confirmed that if errors in measuring the distance between individual UAVs and the group leader are from 0.01 m to 12.0 m, the mean values of group commander position determination errors range from 0.11 m to 34.6 m. The simulation result showed that to accurately determine the group commander’s position, the distance measurement errors between individual UAVs and the group commander must be less than 1.9 m. The research results showed that the telemetry method can be used to determine the position of individual members of the UAV group. The advantage of this method is that it does not require the reception of signals from satellite navigation systems, which can be interfered with under certain conditions. The disadvantage of the method is the need to synchronize the time bases of individual UAVs that communicate in the telecommunications network.