Enabling Safe and Efficient BVLOS Operations

Iridium recently conducted a flight trial in partnership with American Aerospace Technologies to showcase BVLOS capabilities. (Photo: Iridium)

Iridium Communications, a global mobile voice and data satellite communications network, recently published the results of an uncrewed aircraft systems (UAS) flight trial that highlighted beyond visual line of sight (BVLOS) capabilities.

In recent news, Collins Aerospace unveiled its new SATCOM solution to support the Iridium Certus satellite network that replaced the legacy GEN 1 constellation.

Part of Iridium’s commitment to advancing the integration of UAS into the national airspace system (NAS), the flight trial was conducted in partnership with American Aerospace Technologies. The trial affirms that a simplified Minimum Equipment List (MEL) may allow a Remote Pilot-In-Command (RPIC) to effectively monitor missions, communicate with air traffic control, and ensure compliance with safe Instrument Flight Rules (IFR) separation from other aircraft. 

In a white paper titled, “Monitored BVLOS: A New Model for UAS Integration in the National Airspace System,” Iridium addresses the challenges faced in establishing a safe, scalable, and efficient adoption of UAS in the NAS. The white paper explores methods to ensure the secure separation of aircraft. 

The results of the flight trial indicate that BVLOS operations are especially well-suited for Class E airspace due to the significantly reduced risk of encountering crewed Visual Flight Rules (VFR) aircraft. This accomplishment by Iridium marks a significant step forward in revolutionizing UAS integration.

Monitored BVLOS: a new model for UAS integration (Photo: Iridium)

With over 30 years of experience in the aviation industry, John Peterson, Executive Director of Aviation at Iridium Communications, has witnessed numerous advancements and challenges. In an interview with Avionics International, Peterson shared his excitement about the potential of drones and the commercial benefits of BVLOS operations. He offered insights regarding the complexities of flying uncrewed aircraft and the crucial need for the safe integration of UAS into shared airspace.

Peterson remarked first on the difficulties of enabling UAS operations even with a visual line of sight. The absence of a pilot on board raises concerns about potential accidents. “Operating beyond a certain distance within visual line of sight really just isn’t safe, because your depth perception isn’t any good once it gets far away from you,” he explained.

Realizing that operating within visual line of sight had limited commercial applications, he began exploring the possibilities of beyond visual line of sight. He drew a parallel to instrument flight rule (IFR) operations, which involve trained and equipped pilots operating under a well-established set of rules. Inspired by this comparison, Peterson recognized the potential of BVLOS operations and the need for a similar regulatory framework.

However, the challenges lay in congested airspace, particularly over urban areas. Such airspace demands careful consideration from regulatory authorities, given the associated risks. Remote and rural areas offered a more favorable environment for BVLOS operations, with numerous potential applications, Peterson noted. Given this opportunity, there is a need to establish rules, standards, and equipment requirements specifically tailored for BVLOS operations.

He expressed his concerns about the current waiver process for BVLOS operations. The process involves writing and submitting a white paper outlining their plans for operating the aircraft and any associated risks. “Someone needs to review it, and then they have to approve it. There’s no standard for it, so all the equipment that’s inside that document may be unfamiliar to the person who’s reviewing it,” he explained.

Peterson and a collaborative group, comprising avionics providers, OEMs, and software providers, sought to answer the question, “Can we actually maintain safe IFR separation using the highest latency link?” 

The advantage of Iridium’s satellite link, according to Peterson, was that it enables “excellent visibility of an aircraft no matter where it is in the world. These aircraft fly at such low altitudes that they don’t always see the VHF or ADS towers, but they fly at a high enough altitude that they don’t always see the LTE towers.”

He emphasized the importance of augmenting IFR rules to facilitate BVLOS operations under specific conditions through a waiver process. Local airspace authorities would play a pivotal role in approving and monitoring operations within their respective regions. This approach would enhance safety and foster localized oversight, rather than relying on a one-size-fits-all approach.

The goal of the flight test, conducted with American Aerospace Technologies, was to determine if existing Instrument Flight Rules (IFR) and technologies could be leveraged to enable safe BVLOS operations. By analyzing the capabilities of Traffic Collision Avoidance Systems (TCAS) and Airborne Collision Avoidance Systems (ACAS), Iridium assessed the feasibility of maintaining appropriate separation distances. The team examined the time required to respond to intruders and maintain a safe distance based on speed, time, and distance calculations.

The flight test results were promising. Using Iridium Communications’ satellite link, the team found that it took approximately 18 seconds to react to an intruder spotted at a 5-mile distance. This response time allowed for maintaining more than 2 nautical miles of separation, meeting IFR rules even in BVLOS scenarios.

By utilizing existing rules and infrastructure and encouraging continuous improvement, the industry can expedite progress in BVLOS operations. Peterson believes that a limited number of BVLOS waivers issued per day, coordinated across different states, could provide a commercial advantage while ensuring safety and repeatability. This approach allows for iterative improvements in BVLOS operations while the FAA focuses on establishing comprehensive regulations for more complex airspace.

The vision extends beyond rule implementation. Peterson anticipates significant investments from avionics companies, aircraft manufacturers, operators, and software application providers to support BVLOS operations. The collaborative efforts of the industry will contribute to the development of standardized Minimum Equipment Lists (MEL) and the advancement of safer and more efficient BVLOS flights.

“That’s how our industry becomes great very quickly, without us sitting around waiting for a grant,” he said. “That’s the part that Iridium is super passionate about—using technologies that help us advance this incredible industry that’s in somewhat of a lull.”

He also shared his thoughts on how he would like to see the industry evolve over the next few years. “I’d like to see the directors of the local states working with their local operators and their local OEMs in order to establish areas where we can have BVLOS waivers that perform real commercial missions, whether they’re first responders, package delivery, or infrastructure monitoring—real commercial operations.”

He hopes to see these initial operations happening in a very simple way so that people become comfortable with increasing the number of missions per day. Then, the area in which they’re allowed to perform those missions can expand. Another factor is increasing the fidelity of what an MEL is in pilot training. “We don’t have established BVLOS pilot training—we need to define that better,” Peterson said. 

He also hopes that it will be possible to get BVLOS waivers approved using software applications. “We have evolved the MEL in the training to a point where somebody doesn’t need to write a white paper,” he commented. “They just need to be able to prove that they meet the requirements for a BVLOS waiver.” 

“Then what we would see is an economy of scale that’s occurring. We would see so much data from this that the FAA would become comfortable establishing a policy that eliminates the waiver process, and BVLOS becomes a part of our national airspace.”

Peterson outlined what he sees as some of Iridium’s strategic priorities. The first priority is to provide the drone industry with the most advanced and cost-effective satellite communications solutions. By addressing challenges related to size, weight, power, and cost, Iridium aims to offer the lowest-latency and most affordable satellite communication methods for drones. This strategic focus reflects the company’s commitment to equipping drones with the necessary tools to operate seamlessly and communicate effectively over long distances.

Although not in Iridium’s wheelhouse, the integration of 1090 megahertz surveillance systems into the national airspace is important for the industry, Peterson noted. He pointed to the unique advantage of this frequency, which is that satellites have the capability to detect 1090 megahertz signals. Drones, flying at altitudes where ground infrastructure is out of sight, benefit from excellent visibility to satellites. 1090 megahertz technology can be leveraged to enhance situational awareness, ensuring that drone operators have access to real-time information about their own position as well as the position of other aircraft in the vicinity. This integration is crucial for maintaining a comprehensive and accurate view of airspace activity.

Another priority is augmenting existing infrastructure through the use of battery-based Mode S transponders. These transponders, installed in aircraft that are not equipped with traditional transponder systems, enhance visibility and enable the effective relay of crucial information. Peterson suggests that incentives such as waivers, credits, or grants could encourage pilots to adopt this technology. It significantly contributes to the overall situational awareness of the airspace.

By layering the data from various sources, including 978 and 1090 megahertz surveillance, drones can relay valuable information about nearby traffic to air traffic controllers and remote pilots. This cooperative approach enhances safety and ensures that all relevant stakeholders have access to a comprehensive picture of the airspace.

The integration of these priorities offers a pathway to a future where collaboration, data sharing, and innovation thrive. Peterson believes that incremental improvements, rather than massive infrastructure overhauls, can lead to enhanced cooperation and safety in airspace operations. By making existing technology available to pilots, particularly those flying experimental or VFR, the industry can achieve greater synergy between different airspace users. The ability to respond to and cooperate with surrounding traffic becomes more accessible, fostering a conducive environment for BVLOS operations.

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