**4. Structured mathematical model of speed and angle of attack aircraft in a flight simulator**

Current computer technologies allow formulation and solutions to a new intricate problem, which depends on construction of structured mathematical models of aircraft and methods of their solution. Achieving an accurate solution to this problem requires simultaneous solution of the whole complex of physical and geometric problems, which is based on considerable computational resources [16]. Our proposed solution is supported by the above approach, where there are, complex requirements for properties and parameters affecting the design process of a structured mathematical model of aircraft motion on computers.

To create a system of differential equations, it is necessary to know the aerodynamic coefficients, mathematical model of aircraft systems, and other parameters of the aircraft [1, 2]. The contribution in Laplace transform creates a structured mathematical model of aircraft motion in a flight simulator, see [5, 15].

Action of an aircraft elevator control stick angle and throttle control stick displacement on aircraft motion—two control parameters (**Figure 1**) are discussed below. **Figure 1** is a block diagram of already mentioned two-parameter control of a structured mathematical model of motion of aircraft on a flight simulator, which will be the subject of research.

The process of simulation experiments requires finding solutions for individual tasks defined at the beginning of the previous subchapter. The simulation program

**Figure 1.**

*Block diagram of a structured mathematical model of control of aircraft motion – speed and angle of attack.*

**Figure 2.** *Parallel simulation algorithm of simulators' models.*

expresses the time factor in the form of an explicit simulation time and changes the state of model. Two opposite methods of working with simulation time are implemented in the programming technique. In the constant time step method, it is necessary to select a constant real-time interval, which is considered as a unit of simulation time. The structured mathematical models of all simulators need to process the simulation run—the simulating step during this time unit (**Figure 2**).
