Today, the single biggest obstacle to dramatically improving commercial drone operations in the U.S. is the ability to fly Beyond Visual Line Of Sight (BVLOS) of the operator. Nearly every enterprise seriously operating drones today is looking into this capability due to the immediate benefits in terms of efficiency, time savings, and entirely new use cases.
Yet very few companies have successfully obtained permission from the FAA to do so. The few that receive approval are mostly constrained to specific, carefully managed BVLOS test ranges and public aircraft operations rather than the fields and workplaces which can generate ROI-positive results.
Let’s take a look at the current state of long linear drone flights, and why it’s difficult to fly BVLOS today.
The current state of BVLOS drone capabilities
In terms of drone hardware, very little stands in the way of drones’ physical capability to operate and be controlled beyond visual line of sight. Many fixed-wing drones are capable of flying for an hour or more, and even the roughly 30-minute flight times of typical quadcopters is enough to carry them several miles. And now that drones capable of connecting to cellular networks are hitting the market, command and control is possible from virtually anywhere with a network signal.
The biggest obstacle to BVLOS flights, then, is regulatory, not technological. Part 107 forbids the operation of drones beyond visual line of sight of the pilot in command, unless the pilot is operating under a waiver from the FAA. That waiver has proven extremely challenging for businesses or individuals to obtain.
For drone operators wishing to fly BVLOS, the FAA wants to see them address both the air and ground risks. While there are various approaches to minimizing ground risk, such as using parachutes or operating over remote areas or areas with limited access, minimizing air risk remains the biggest challenge for the industry.
Minimizing the air risk usually means employing some sort of Detect And Avoid (DAA) technology. Radar is usually the most straightforward way to detect other aircraft. Indeed, the FAA operates its own Air Traffic Control system based on radar and a new NextGen system called ADS-B to ensure traffic separation. However, this system is designed for crewed aircraft, which are larger and operate at higher altitudes, and the FAA explicitly bans drones operating under Part 107 from broadcasting ADS-B signals.
Since flying with this system is outside the scope of Part 107 drone operations, what kinds of DAA technologies are available for drone pilots?
Skyward’s experience: BVLOS flight in a limited area
In 2020, Skyward implemented a ground-based radar system in support of a first-of-its-kind BVLOS drone operation to prove out a use case that would monitor critical communications infrastructure. The network-connected drone system we deployed allowed us to evacuate personnel from the area during an emergency, yet operate the system completely remotely with no on-site visual observers or support personnel.
We obtained permission for this operation through the FAA’s Special Governmental Interest process. This resulted in a short-term Part 107 BVLOS waiver that allowed us to monitor specific critical infrastructure sites under a Temporary Flight Restriction (TFR) during an emergency. This system consisted of a Percepto drone system, Fortem radar, weather station, remotely operated camera, and a doppler weather radar system.
Skyward’s BVLOS operations were made possible through significant capital investment and many months of planning. However, even this system and its successfully temporary deployment has not been sufficient in the eyes of the FAA to warrant a more permanent BVLOS waiver.
The challenge of detect-and-avoid technology for long linear inspections
Regardless, this limited-area approach would not seem to be scalable for long linear infrastructure such as pipelines or transmission lines. Our ground-based radar system is able to detect a Cessna 172-sized aircraft out to about a 3.7 statute mile radius (a little over 7 mile diameter). However, covering long distances with this system — for example, a 100 mile pipeline — would require dozens of radar stations. These would be prohibitively expensive and would require their own power and connectivity.
Additionally, it is still not a settled question if detecting only crewed aircraft is sufficient. The FAA argues that, to operate completely BVLOS, the system will have to also detect much smaller aircraft such as other drones or even large birds, since collisions with these could create a ground hazard that must be mitigated.
There are companies working on an aircraft-mounted radar system for DAA; these are large, heavy, expensive, and have limited range. It is not clear if they would fit on a drone within the limits of Part 107 (under 55 pounds), and they may be prohibitively expensive. For example, take a potential drone-mounted system that can detect a Cessna 172-sized aircraft out to about 1.5 kilometers (about 1 statute mile). Considering the potential closing speeds involved, this leaves little time for the drone to execute evasive maneuvers.
These systems have not been proven effective in U.S. airspace, let alone approved by the FAA. Furthermore, each effort must be individually reviewed and approved since there is no standardized regulatory path to approve DAA or operate BVLOS. Given the costs and constraints, Part 107 BVLOS drone operations today would seem to be more expensive than operating crewed aircraft.
Laying the foundation for future BVLOS missions at your company
In light of what I’ve said so far, long-distance BVLOS infrastructure inspections may be impractical for most companies today. However, the drone regulatory environment continues to evolve, and DAA technology is continuing to develop. The question becomes how to execute a drone strategy that is ready to take advantage of these innovations and paves a path to get to BVLOS operations. The goal is to derive value from your program today while making progress towards BVLOS flights tomorrow.
Program maturity is an important factor when the FAA considers waivers for advanced drone operations. In fact, we’ve seen that the FAA may deny a Part 107 waiver to a given entity even though they are using the exact same equipment and concept of operations as a waiver granted to another more experienced organization.
At this point in time, we believe that most companies should be focusing on this goal: to build up a robust program, on a foundation of safety and real-world experience, that is proven capable of safe complex operations. This foundation can be leveraged to operate BVLOS as soon as the regulator allows. As a member of the FAA’s BVLOS Aviation Rulemaking Committee, we are excited for the committee’s report to the FAA, and hope to see rulemaking that enables BVLOS operations in the not-so-distant future!
Our practical recommendation today? Pursue an EVLOS waiver
One of the best ways to prepare for BVLOS operations is with EVLOS (Extended Visual Line Of Sight) flights. EVLOS operations involve flying drones long distances while being closely monitored by observers. These operations still require a waiver; however, it is much easier to obtain than a BVLOS waiver.
There are two main methods for monitoring EVLOS flights. The first is to employ a chain of visual observers to keep an eye on the aircraft from various points along its course. The second method is to use several visual observers to scan the environment for other aircraft, without necessarily observing the drone itself. This requires the pilot and visual observers to know precisely where the drone is at all times, perhaps using a capability like Skyward’s Live Flight Tracking to monitor near-real time telemetry data.
EVLOS flights can help you evaluate what drones can do from a use case perspective. Companies operating under an EVLOS waiver will gain experience operating different aircraft and sensors over varying distances, which will allow the evaluation not only of the aircraft, but also of the types of imagery and analysis products that are available.
EVLOS operations over longer distances will also allow the evaluation of connectivity options for aircraft command and control. While it’s a common belief that cellular connectivity is non-existent in very remote areas, our experience with airborne operations is that cellular connectivity is frequently better at drone altitudes and can be available even when there may not be coverage at ground level. Operating aircraft under an EVLOS waiver allows companies to measure and evaluate cellular coverage as an alternate means of command and control in the areas of interest.
Most of all, conducting the above evaluations and routine data gathering over time would help establish program maturity. It will be necessary to show the FAA your program’s experience and maturity regardless of how much DAA technologies evolve.
Want to learn more about the latest in long-distance command and control for drones?
Download Skyward’s White Paper, Next Gen Drone Ops: Connecting Drones to the Verizon Network.