Beyond visual line of sight (BVLOS), operations are expanding the capabilities of the drone industry. Missions that were previously limited to visual line of sight, or VLOS, have begun to unlock new possibilities thanks to BVLOS operations. As the industry continues to move towards more autonomous solutions, understanding the technology, the regulatory requirements, and the benefits of BVLOS operations is an important step for organisations looking to scale their business.
What is BVLOS?
Beyond visual line of sight, or BVLOS, refers to the ability to perform unmanned aircraft system (UAS) operations without requiring a drone pilot or operator to maintain constant and direct visual sight of the aircraft. BVLOS operations enable operators to control and monitor aircraft such as drones and eVTOLs from control stations using specialised technology solutions.
BVLOS Technology
There are several main components when it comes to BVLOS drone operation technology:
Detect and Avoid Technology
Drone operators intending to fly BVLOS may be required to mitigate the risk using detect and avoid (DAA) technology. During BVLOS drone operations, a DAA system allows drone operators to detect and avoid obstacles such as other aircraft automatically or autonomously. DAA uses sensors such as radar, acoustic and optical to ensure that the UAS keeps a safe distance from any obstacles encountered in the airspace.
It can rely on ground infrastructure such as radar systems to enhance situational awareness, navigation and operational safety. Ground-based external radars can supplement the limitations of the drone’s on-board sensors in BVLOS operations.
Drones can also have integrated technology, such as ADS-B (Automatic Dependent Surveillance-Broadcast), which transmits information including speed, the direction of flight, the drone’s attitude (orientation to the horizon) and altitude (vertical height). Pilots can also change the flight parameters and control sensors to collect data., But they can also be equipped with other technologies such as Transponder MODE-S, FLARM, radars and other devices that could be considered helpful to the mission and feed into the overall DAA system.
Communication Technology
For BVLOS flights, operators must have a reliable radio link between the remote pilot and the UAS to record important safety data and have a means of communication with the air traffic control centre for airspace access. This is often known as command and control (C2) technology or control and non-payload communication (CNPC).
Geofencing
Geofencing is a software-based technology that creates virtual borders around specific geographical areas. These borders can be integrated into a drone’s system to automatically prevent the drone from entering no-fly zones, which is crucial to BVLOS operations.
Airspace Awareness Tools
U-space, a designated airspace for drone operations, created to manage and coordinate automated drone flights supported by a USSP system or other ways of UTM systems provides a set of services and systems designed to manage the safe and efficient use of UAS in the airspace, particularly in low-altitude environments. This tool provides real-time information about the surrounding airspace, including data on active air traffic, restricted airspace, temporary no-fly zones, weather conditions, and other relevant flight information.
Using a U-space service provider (USSP) while flying reduces the air risk of the operation because the traffic operating within the airspace is known. The U-space service can mitigate the air risk class (determined by SORA) by providing situational awareness, traffic information, and strategic deconfliction, making it a benefit for BVLOS operations.
Remote ID
Direct Remote ID is a broadcasting system that transmits the identification and location of a drone in flight in real-time. The information transmitted can be received by airspace authorities, law enforcement and other industry stakeholders. This is relevant to BVLOS flights as it will help to prevent mid-air collisions and unauthorised airspace entry. However, it must be noted that as of November 2024, the apps and interfaces that support this broadcasting are not very advanced in their development. The range of the devices is currently limited to under 1km due to Bluetooth and WiFi constraints, meaning that drones flying BVLOS cannot transmit or detect larger distances.
Alternatively, Network Remote ID is an identification process that connects drones to the internet using an app or directly through an operator control station. It allows the drone’s data to be identified via an online system. Network ID is required within U-space airspace and can be used in control centres further away from the operation, enabling more opportunities for BVLOS missions.
Drone Dock and Automated Drone Stations
Drone docking stations allow UAS to take off and land and provide a recharging facility for the aircraft. They can be set up in remote areas, which is ideal for BVLOS operations and have integrated technology such as geofencing, DAA systems and airspace awareness tools. The charging process, controls, and operations can be automated, allowing many drones to fly simultaneously. Some docking stations provide an enclosure that can store and protect the drone, which increases the flexibility of BVLOS missions.
What Does BVLOS Mean for European Regulations?
There are currently 2 European Regulations concerning drones within Europe: Delegated Regulation (EUR) 945/2019, which legislates the design and manufacturing standards for unmanned aircraft systems (UAS), such as class marking, and Implementing Regulation (EU) 947/2019, which defines the requirements and procedures for drone operations, including the determination of risk.
The European Commission has divided all drone operations within Europe into three categories: open, specific, and certified. A drone’s operation can be characterised using a chart such as this one:
BVLOS drone operations are classified in the specific category, which allows drone operations of moderate risk to obtain authorisation with more operational flexibility while maintaining the required safety standards. Any operation intending to fly BVLOS is automatically classified in the specific category and may be required to undergo various paths to receive authorisation, such as:
The SORA method was developed by the Joint Authorities for Rulemaking on Unmanned Systems (JARUS), which, at the time of inception, was led by Murzilli Consulting’s CEO, Lorenzo Murzilli. The methodology evaluates factors such as air and ground risks as well as their mitigations to determine if the operation is lower risk (SAIL I and II), medium risk (SAIL III and IV) or higher risk (SAIL V and VI).
A PDRA simplifies the approval process for certain drone operations by providing a pre-assessed and predefined set of risk mitigation measures and safety requirements for specific operational scenarios. EASA has published a list of their currently approved PDRAs (4 of which apply to BVLOS operations), with visual accompaniments such as the example shown below:
**Image from EASA Predefined Risk Assessment (PDRA)**
STS, or Standard Scenario, is a set of predefined operational conditions and safety requirements created by EASA, where if the operation meets the requirements, it does not need an additional risk assessment or operational authorisation. There are currently 2 STS that have been published. Relevant to BVLOS operations is the STS 02: BVLOS with Airspace Observers Over a Controlled Environment. Appendix 1 Chapter 2 of Regulation (EU) 2019/947 contains the full list of requirements, including the CE class identification label.
Class marking could be something that needs to be considered before conducting a BVLOS drone operation. Although Delegated Regulation (EU) 2019/945, states that a drone must be classified into one of the 7 C-mark classes (CO- C6) to be sold in the European Economic Area (EEA) for the use in the open category, the C6 class mark is relevant for BVLOS operations.
A class-marked UAS may provide benefits for operations in BVLOS in the specific category, where some flights may require additional risk mitigation such as parachutes, geocaching and flight termination systems for emergency protocols. A C6 C-mark enables BVLOS flights considered to be of lower risk to be operated under European Standard Scenario (STS) 02, while BVLOS flights in the medium risk (SAIL IV) or higher risk (SAIL V and VI) will not require c-marking but need to comply with more stringent verification procedures such as a design verification report (DVR) or a type certificate (TC).
**Image from EASA Standard Scenario**
What are the Benefits of a BVLOS Operation?
A BVLOS operation has several advantages over a VLOS operation, given that the drone can travel further, beyond the operator’s visual line of sight. Currently, BVLOS flights are primarily used to monitor large spaces (surveillance), deliveries, search and rescue, mapping, data collection and inventory. A BVLOS drone operation for these types of missions could be cost-effective, safer and more efficient due to its ability to fly with minimised human interference.
Another benefit of BVLOS drone operations is that it is significantly cheaper than using a crewed aviation service such as a helicopter or an aeroplane. For long-range aerial data collection, a drone can fly at a lower altitude than a crewed aircraft or satellite, producing higher-resolution results.
First responders or inspectors can also benefit from BVLOS missions. Sending a drone into an uncertain or hazardous situation can better prepare the team prior to entering, or even enable them to view an area that a human cannot physically access, which will improve safety, efficiency and could be a more cost-effective solution.
Finally, the technology that is constantly being upgraded and developed within the drone industry enables operators to control variables such as timings and risks such as cybersecurity breaches, which improves the overall efficiency and safety of the mission.
What Authorisations are Required for a BVLOS Operation?
BVLOS operations require several varied steps to be considered authorised for a mission. The specific authorisations will vary depending on several factors, namely how they are categorised once the risk factor has been determined.
ConOps
This details the drone’s operational use, which includes mission scenarios, responsibility and emergency protocols.
Risk Assessment
This evaluates the level of risk involved with the mission. All BVLOS missions will be classified in the specific category, meaning that the Specific Operation Risk Assessment (SORA) method will be applied and used for the authorisation process. The SORA will assess if the operation is lower risk (SAIL I - II), medium risk (SAIL III - IV) or higher risk (SAIL V - VI). Depending on the SAIL classification, there will be additional requirements such as TC for SAIL V/VI and DVR for SAIL IV.
Training
Pilots are required to meet additional training requirements to fly BVLOS drone operations. The remote pilot must hold a valid Remote Pilot Certificate of Competency for the category that they intend to fly in. This requires them to first learn navigation of uncrewed flights, meteorology, flight performance and planning, and flight rules.
**Note: Depending on the National Aviation Authority (NAA) there may be additional training requirements.**
Approvals and Flight
After the previous steps are completed and the supplemental documentation has been provided to the authority’s satisfaction, approval will be granted for the operation.
How Can Drone Consultants Support BVLOS Operation Approvals?
Regulation is one of the most challenging factors in BVLOS missions. The dynamic nature of the industry and its rapidly evolving technology can make authorisation and airworthiness tasks time consuming and costly.
A drone consulting firm such as Murzilli Consulting can provide up-to-date regulatory information and prepare the applicant for all the necessary steps involved in any required regulatory action, including operational planning, risk assessment management and technology integration support. Murzilli Consulting has several custom-built services that are relevant in securing authorisation and airworthiness for BVLOS missions:
SORA
This service is for the risk assessment phase of drones in the specific category. Murzilli Consulting’s team of experts can guide applicants through gaining operational authorisations for any SAIL level, including complex SAIL III, IV, V and VI applications. This is a 9-step service that supports organisations from the initial assessment and ConOps to the final application phase.
LUC
This service provides support for the applicant in obtaining the optional Light UAS Operator Certificate (LUC). Murzilli Consulting can support the establishment, implementation and maintenance of a Safety Management System and aviation authority liaison.
DVR/TC
This service is for SAIL IV operations (DVR) and SAIL V and VI operations (TC) and has 2 phases. In phase 1, Murzilli Consulting’s expert consultants assess the applicant's design review and design management system. Once this preliminary phase is complete, phase 2 is the preparation and submission of the design verification to EASA to obtain the DVR.
UAS C-Class and CE Marking
This service is designed to accelerate the certification process for class marking (known as ‘Class Identification Label’ by Delegated Regulation (EU) 2019/945) and reduce time and effort while coordinating with the notified bodies. It focuses on 4 steps: the familiarisation phase, design and document review, gap identification and testing phase and final gap analysis and gap closing procedure to ensure an organisation’s drone is correctly certified and the process is managed smoothly.
Murzilli Consulting offers a wide range of services that can support organisations considering BVLOS operations. For a full list of our services, click here, or write to us, and we would be happy to answer any questions.
