Open Access Open Access  Restricted Access Subscription or Fee Access

Specific Category Operations Within the U-Space: Expert Systems Embedded Within RPAS as an Original Mean of Mitigation of Operational Safety Risks

(*) Corresponding author

Authors' affiliations



This article describes a mitigation strategy against the risks potentially caused by RPAS capable of performing Specific Category of operations within not segregated airspace. A selection of hazards has been associated to these RPAS and it has been assessed thus obtaining a risk matrix. Considering the basic principles of risk analysis management based on Safety Management System theory, after having implemented the matrix (risks identification and ranking), a new mitigation strategy has been defined in order to maintain constantly the hazards consequences at or below an acceptable level. A strategy based on ‘Expert Systems’ has been chosen. ‘Expert Systems’ are computer systems capable of suggesting solutions to problems emulating human expertise in a given field of knowledge. There are many typologies of ‘Expert Systems’; the ones considered in this article are the rule-based ‘Expert Systems’. They are characterized by a basis of knowledge built from set of rules expressed as ‘IF’-‘THEN’ statements. In this case, each statement has been directly implemented from the operational risks contained in the matrix with a one-to-one correspondence between mitigating rules and hazards for a given RPAS capable of performing Specific Category of operations. The novelty of this process is deemed to be the idea of laying down the basis for the implementation of a software based on artificial intelligence (the ‘Expert System’) to be integrated with the Flight Control System/Autopilot Subsystem of the RPASs object of the original risk assessment in order to recognize risks and promptly mitigate them during the execution of operational sorties within not segregated airspace. Two levels of integration (basic and advanced) are described and discussed in the article.
Copyright © 2021 Praise Worthy Prize - All rights reserved.


RPAS; Integration; Not Segregated Airspace; Risk Matrix; Safety; Expert Systems

Full Text:



European Aviation Safety Agency (EASA), Special Condition Light Unmanned Aircraft Systems, SC Light-UAS 01, Issue: 1, (© EASA, Cologne, 2020).

International Civil Aviation Organization (ICAO), Doc. 9859/AN 474, Safety Management Manual (SMM), third ed. (© ICAO, Montreal, 2013).

International Civil Aviation Organization (ICAO), Doc. 10019/AN 507, Manual on Remotely Piloted Aircraft Systems (RPAS), first ed. (© ICAO, Montreal, 2015).

F. Bonfante, Safety Management System for light RPAS, Analysis of a real case: study on the safety and the integration in the civil airspace with an evaluation of the regulatory impact in Italy, Doctoral dissertation, Dept. Aerosp. Eng. Politecnico di Torino, -Turin, Italy, 2019.

European Safety Aviation Agency (EASA), Easy Access Rules for Unmanned Aircraft Systems (Regulation (EU) 2019/947 and Regulation (EU) 2019/945), (Cologne, 2020).

Dutta, A., et al., Expert Systems, FIETE, (2015), 31-37, Published online.

Masri N. et al., Survey of Rule-Based Systems, IJAISR, 3 (7), (2019), 1-23,

Kaczor, K., et al., Overview of Expert System Shells, Institute of Automatics, AGH University of Science and Technology, Inzynieria wiedzy, Kraków (Poland), (2010).

Tripathi, K. P. A., Review On Knowledge-based Expert Systems: Concept And Architecture, IJCA, (2011).

Sharma, T., et Al., Study of Difference Between Forward and Backward Reasoning, International Journal of Emerging Technology and Advanced Engineering (ISSN 2250-2459), Volume 2, (2012).

Arani, L. A., et Al., Intelligent Computer Systems for Multiple Sclerosis Diagnosis: a Systematic Review of Reasoning Techniques and Methods, Acta Inform Med. 26(4), (2018), 258–264

Munaiseche C.P. C., et Al., An Expert System for Diagnosing Eyes Diseases Using Forward Chaining Method, IOP Conf. Ser.: Mater. Sci. Eng. 306 012023, (2018).

G. C. Philip, Guidelines on Improving the Maintainability and Consultation of Rule-based Expert Systems, Expert Systems with Applications, (1993), 169-179. (accessed on the web on the 3rd October 2018).

SESAR Joint Undertaking, U-Space Blueprint (Luxembourg, 2017).

International Civil Aviation Organization (ICAO), Circular 328/AN 190, Unmanned Aerial Systems (UAS), first ed. (© ICAO, Montreal, 2011).

J Liebowitz, The Handbook of Applied Expert Systems, (, 2019)

Leveson, N. G., Engineering a safer world: systems thinking applied to safety, (The MIT Press, Cambridge, 2011), accessed on web on 24 June 2017.

Ajay K. S., Review of Expert System and Its Application in Robotics, Intelligent Communication, Control and Devices, (2018).

Hettiarachchi C. et Al., A Systematic Requirements and Risks-Based Test Case Prioritization Using a Fuzzy Expert System, IEEE 19th International Conference on Software Quality, Reliability and Security (QRS), Sofia, Bulgaria, pp. 374-385, (2019).

Hadjimichael M., A Fuzzy Expert System for Aviation Risk Assessment, Naval Research Laboratory, Marine Meteorology Division, Monterey, Expert Systems with Applications 36, 6512–6519, (2009).


  • There are currently no refbacks.

Please send any question about this web site to
Copyright © 2005-2024 Praise Worthy Prize