BVLOS

BVLOS, or beyond visual line of sight, refers to the operation of unmanned aircraft systems (UAS) when the aircraft is outside the operator's unaided visual range. In BVLOS operations, the pilot cannot see the aircraft and must rely on a combination of telemetry, sensors, and airspace coordination to maintain safe flight and separation from obstacles and other air traffic.

Safe BVLOS flight typically depends on detect-and-avoid capabilities, robust data links, automated flight-planning and monitoring, and integration with airspace management systems. Operators may employ onboard sense-and-avoid sensors, ground-based observers, or a combination of both, along with redundant communications and emergency failure procedures. A regulatory authority may require a safety case and demonstration that risks are mitigated to an acceptable level.

Regulatory context: Most jurisdictions require a specific authorization or waiver to conduct BVLOS operations outside authorized test areas. Requirements commonly include operator and pilot certification, aircraft airworthiness, maintenance, remote identification, and contingencies for loss of link or degraded sensor performance. Some regimes also emphasize risk assessments, geofencing, and coordination with air traffic control or UTM systems.

Applications: BVLOS enables long-range inspection of infrastructure, delivery and logistics, agricultural monitoring, search and rescue, and disaster response, particularly in areas or conditions where visual contact is impractical or unsafe.

Challenges: Technical limitations in DAA accuracy, latency, and reliability; airspace integration and safety oversight; weather sensitivity and night operations; high cost of equipment and certification; and public and political acceptance. Ongoing research aims to improve autonomous navigation, performance-based regulation, and scalable UTM frameworks to expand BVLOS while maintaining safety.