In the drone industry, there are a lot of technical terms that a drone enthusiast or operator should comprehensively understand in order to be competent. Some of the fundamental terms are Visual Line of Sight (VLOS), Extended Visual Line of Sight (EVLOS) and Beyond Visual Line of Sight (BVLOS). It is imperative to identify ahead of the flight type to the mission format in order to properly plan and execute the mission as well as requirements in terms of specific permits from the Aviation Authorities in the dedicated area. Basically, grasping the differences aids in knowing the regulations and requirements as it ensures compliance with laws and regulations, and to maintain air traffic safety, privacy and security.
To begin with, VLOS is when the remote pilot is able to clearly see the Unmanned aircraft or drone and the surrounding airspace always at any point while it is airborne. In a nutshell, the main objective of VLOS is to ensure that the operator has full awareness of the drone’s position, movements, and surroundings, and can make accurate judgements about its trajectory and potential hazards. As such, this requirement for a drone is critical in increasing safety and since the operator can see the drone, they have greater control. However, it has a limited range as the operate must be able to see it all the times and this restricts the applications for which the drones can be used. To add on, the nature of the process results in increased workload by maintaining sight which can cause fatigue and may require additional personnel.
On the other hand, EVLOS refers to the type which enables operating a drone further than VLOS where one or more visual observers is required and the latter must be trained and instructed. As it involves a number of people, communication is a vital aspect because throughout the flight, observers keep a visual contact with the drone and communicate with the drone operator about observations and alerts the pilot if necessary. Alternatively, a pilot can use extra solutions such as first-person view (FPV) equipment to transmit a live camera feed of the surrounding area back to an operator though the option provides limited depth perception and peripheral vision. Better yet, more sophisticated technologies include fully automated detect-and-avoid solutions which combines an array of cameras with high-end computer vision and machine learning. On a fundamental level, EVLOS offers greater range and flexibility in drone operations compared to VLOS but still upholds the safety aspects of VLOS; nevertheless, the safety is way better and operations are more efficient.
Lastly, BVLOS is essentially the opposite of VLOS and simply put, it refers to operations where the drone is flown outside the pilot’s visual line of sight therefore, they rely on other mean such as cameras, sensors and communication links to monitor and control the drone. When it comes to BVLOS, pilots are trained differently in a sense that they need to possess theoretical and practical training of navigation on unmanned flights, meteorology, flight performance and planning, and flight rules. The primary benefit of BVLOS flight is that it enables a drone to cover far greater distances as such, it is ideal for last mile delivery logistics, excellent for search and rescue missions, perfect for environmental mapping, optimal for disaster management among others. However, BVLOS flights are not allowed in most countries and the application and approval processes tend to be tough, which leaves most companies unable to take advantage of them. But countries are recognizing how crucial BVLOS is development-wise therefore, they are amending their drone policies so that they can allow UAVs to beyond visual line of sight for maximum.
Summarily, it is important to know the differences between VLOS, EVLOS and BVLOS considering they have different regulations and requirements, and they can affect the types of drone operations and pilots are allowed to performance. Further, since drone technology is developing rapidly , that calls for amended or new policies for governing the initiatives especially BVLOS flights as they have demonstrated the potential to significantly contribute to accomplishing various sustainable development goals (SDGs).