To address this situation, the European Aviation Safety Agency (EASA) has adopted a specific procedure. SORA, the Specific Operations Risk Assessment methodology designed by EASA. establishes 24 Operational Safety Objectives (OSOs) necessary to ensure safety in UAS operations involving medium risk.
In this article, we explore the key aspects for UAV Navigation-Oesia Group’s flight control system to meet these challenges.
SAIL classification
To understand the situation, let’s first look at how flight operations are classified in relation to the risk involved.
EASA establishes six levels of operational risk depending on the type of operations and platforms to be used. The so-called SAILs (Specific Assurance and Integrity Levels) entail a series of specific demands and requirements.
- SAIL I and SAIL II are considered low-risk operations low riskwhere the requirements are less stringent. This is because the risk assessment of the operation determines that the risk of the operation is lower.
- SAIL III and SAIL IV correspond to medium-risk operations medium risk. These operations require more exhaustive compliance with OSOs, design verifications by EASA in the case of SAIL IV and the use of more advanced technologies with specific and more demanding safety controls.
- SAIL V and SAIL VI refer to high-risk operations high risk. At these levels, procedures, authorizations and certifications specific to manned aviation are applied, with rigorous security measures and exhaustive and strict operational controls to mitigate possible risks.
Definition of Means of Compliance (MoCs)
The Means of Compliance provide guidelines and evidence to meet security objectives. to regulatory authorities. Specifically, they present practices to meet the 24 Operational Safety Objectives and mitigate the risks of UAS operations to the maximum extent possible.
Although their adoption is not mandatoryAlthough their adoption is not mandatory, as UAV manufacturers may propose alternative methods of compliance, MoCs establish a clear framework for implementing safety measures and generating the necessary evidence for operational approval.
What MoCs apply to the design of flight control systems for SAIL III and SAIL IV levels?
Already published and approved by EASA four MoCs that significantly affect the design and the design and operation of flight control systems within SAIL III and SAIL IV operational levels.
As mentioned above, at the SAIL III level, the MoCs specify the SAIL III level, the MoCs specify accepted forms of to demonstrate compliance with the OSOs, without the need for design verification by EASA. Below are the MoCs that are particularly relevant for SAIL III level:
- MoC OSO #5. Evaluates and monitors risks arising from technical failures of the UASrequiring evidence that demonstrate that the probability of losing control is extremely low. For this, methodologies such as Fault Tree Analysis (FTA), Functional Hazard Assessment (FHA) and Failure Mode and Effects Analysis (FMEA) are used.
- MoC OSO #6. It assures that the Command and Control (C2) systems are adequate and sufficient for the operation ..
- MoC OSO #18. Search for the automatic protection of the system against human errors that could cause loss of control of the UAS.
- MoC OSO #24. Mitigates the impact of adverse environmental conditions through the design of the UAS. To verify the correct performance of the system, the MoC suggests performing laboratory and/or flight tests that meet the required standards to demonstrate that the UAS can operate safely in unfavorable environments.
In the case of medium risk operations SAIL IVIn addition, design-related OSOs require verification by EASA. From a flight control system design point of view, we must take into account MoC SC Light-UAS.2510. Linked to OSO #5, this MoC states that systems and equipment should minimize threats in the event of probable failures, avoid catastrophic failures due to singular failures, and have mechanisms to detect and manage combined failures. In SAIL IV, the requirements are higher, requiring that the probability of loss of control due to technical failures be less than 10^-5 per flight hour. .
UAV Navigation-Oesia Group’s contribution to the safety of UAS operations
Faced with the challenges described above, the flight control systems of UAV Navigation-Oesia Group:
- Employ advanced algorithms that detect and manage risksensuring fast and effective responses. In addition, they are designed with redundancies and automatic mechanisms to regain control in critical situations.
- They are distinguished by the use of robust data protocols, guaranteeing the security and integrity of the transmitted information, and have the and have the possibility of configuring redundant data links to improve the reliability of communications.
- They include a flight envelope control and limitationThe control of the parameters (speed, altitude…) that affect the safety of the flight. This is achieved by limiting maneuverability and performance as a function of flight mode and conditions, which reduces the risk produced by commands incorrect control commands by the remote pilot.
- They have been subjected to rigorous reliability tests under extreme operating conditions.
And in relation to medium-risk SAIL IV medium risk operationsthe flight control systems VECTOR-600 and VECTOR-400 of UAV Navigation-Oesia Group are equipped with advanced sensor fusion algorithms and navigation logics. equipped with advanced algorithms of sensor fusion and navigation logics.These systems are designed to complete missions successfully, ensuring safe operation in complex environments, even in the face of combined sensor failures. These systems are designed to complete missions successfully, ensuring flight safety in any operational mishap.
In conclusion
In view of the EASA regulation, integrating the MoCs derived from the SORA methodology in the design of flight control systems is key to ensure the safety of medium risk operations. control systems is key to ensure safety in medium risk operations.. If we follow the practical guide that these requirements set out, we can opt for the authorization of UAS to be able to develop complex operations in a simple and safe way.
UAV Navigation-Grupo Oesía, with its wide technical experience, regulatory knowledge and trajectory in the development of safe and robust products, is an indispensable ally in the complex process of authorization of medium risk unmanned operations. indispensable ally in the complex process of authorization of medium risk unmanned operations. (SAIL III and SAIL IV). By continuously evaluating and adjusting our systems in accordance with the evolution and maturity of current regulations, we maintain the high standards of safety and operational efficiency demanded by the most demanding airline agencies around the world.
Laura García-Junceda, Flight Control Engineer of UAV Navigation-Grupo Oesía.