**Author details**

Maximum Mach number can be defined from the conditions of aeroelastic effects and vibrations, effects of shifting aerodynamic center, causing severe pitching moments, which can lead to the crashes, or loosing effectiveness of aerodynamic surfaces. For example, for jet aircraft L-39 the critical Mach number is *M* ¼ 0*:*8 and exceeding this condition leads to the shift of aerodynamic center of L-39, which generates pitching moment, causing a descending flight with acceleration [3]. To prevent such unstable flight, on L-39 air brakes are used, which automatically act at the Mach numbers *M* ¼ 0*:*78. The critical Mach number is defined at airspeed flight that leads to generation of shock waves on the wing due to the

Finally, an example of flight envelope for analysis is presented in **Figure 17**

The material described in this chapter involves flight vehicle analysis using graphical and analytical tools for better understanding of the physical aspects of flight core parameters and development of strong and meaningful connections between them. The material from this chapter can be useful in the preliminary design and prototyping of flight vehicles and for finding the paths for further

In this work, the name of Prof. Nikolay Zhukovsky (January 17, 1847–March 17, 1921) is mentioned many times, while his name may be unfamiliar to many readers. Nikolay Zhukovsky was one of the first scientists who established the mathematical

base of aerodynamics; he was the initiator and the first head of the Central

acceleration of airflow on the upper surface of wing.

developments and improvements in the design.

**5. Conclusion**

**Figure 17.**

*Aerodynamics*

*Example of a flight envelope.*

**Acknowledgments**

**168**

where the intersection of all limiting conditions is described.

Aram Baghiyan Improvis Aerospace and Defense LLC, Yerevan, Armenia

\*Address all correspondence to: abaghiyan@improvismail.com

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
