Beyond Visual Line of Sight (BVLOS) Ops – the way forward for successful commercial drone operations

Beyond visual line of sight (BVLOS) operations are touted to be the next big advancement that would ensure an effective and successful unmanned aircraft system (UAS) industry, especially commercial UAS operations.

Most commercial UAS operations today are conducted under 14 CFR Part 107, highlighting limitations on minimizing air and ground risks. A maximum altitude of 400 ft AGL, visual line of sight of the aircraft and operations only during the day are some of the limitations outlined and a recent rule allowing limited operations over people.

Representative | Unmanned Systems Technology

The ability to fly drones Beyond the Visual Line of Sight (BVLOS) represents the next ample opportunity for commercial drone operators. Most commercial drone applications are poised to benefit immensely from BVLOS  while some applications would remain impossible to execute without BVLOS.

It is also to be noted that BVLOS operations are prohibited at the moment unless special permissions are obtained from the concerned regulations.

Visual Line of Sight (VLOS), Extended Visual Line of Sight (EVLOS) and Beyond Visual Line of Sight (BVLOS) etc are some of the commonly used terms within the drone industry. So, what exactly do they mean?

VLOS (Visual Line of Sight)


Visual Line of Sight (‘VLOS’) operations are a type of UAS operation in which the remote pilot maintains continuous, unaided visual contact with the unmanned aircraft.

The person operating the drone UAV needs to maintain a visual line of sight with the aircraft at all times, be able to see the surrounding airspace in which the aircraft is operating and operate the aircraft below the cloud base or fog, or smoke etc. In other words, the aircraft must always be visible to the pilot. 

The Regulations in the UK and Europe create an offence to operate an Unmanned Aircraft outside of permitted rules and procedures- a breach of which could carry significant penalties.

EVLOS (Extended Visual Line of Sight)

Mode of operation where a pilot is always present on a location with one or more external observers keeping the UAV in their line of sight.

Representative | Airborne Drones

These observers communicate critical flight information through radio to assist the pilot in maintaining a safe distance from other air users, both manned and unmanned, as well as structures, terrain and other hazards.

BVLOS (Beyond Visual Line of Sight)

In BVLOS, the UAV is allowed to operate away from the visual range, based on instrumentation such as onboard cameras and detect-and-avoid technologies.

In this mode of operation, the aircraft no longer has the protection of the pilot or observer to avoid terrain, obstacles or other aircraft (called ‘See and Avoid’ or ‘Detect and Avoid’ (DAA)).

BVLOS Ops require meticulous planning by the operator with a definite framework process in place with most Aviation Authorities.

In May 2020, the SOARIZON by Thales team collaborated with drone deliveries provider Skyports, to perform a ground-breaking, first of kind, BVLOS medical drone delivery trial.

This trial has proven tangible, real-world, value to the NHS, during its most challenging time in living memory.  We have proven that by working collaboratively with the Government and Regulator that BVLOS drone services can be conducted in a safe and secure method and applied to time-critical use-cases across a number of sectors.  We are looking forward to continuing to develop the service and capability to define future service

Karim Cosslett, Head of Growth, SOARIZON by THALES

BVLOS is also crucial to operating at a higher aircraft-to-pilot ratio, which is an essential economic component of the future feasibility of the industry.

Existing rules basically don’t fit the requirements for full implementation of commercial UAS capabilities. The current regulations still limit UAS use cases

said Jon Damush, CEO of Iris Automation, Inc., a safety avionics technology company pioneering detect-and-avoid systems and aviation policy services

The FAA was scheduled to hold a public meeting on UAS BVLOS on June 22 through its YouTube channel and Facebook page to provide the public with an opportunity to submit written comments or request a timeslot to provide oral comments.

Currently, BVLOS operations are trapped in a regulatory Catch-22. Data must show BVLOS operations can be conducted safely in order to operate, but the only way to obtain that data at scale is to allow BVLOS operations to occur

JON HANLON, Director of UAS Maintenance and Airworthiness, Zipline

The way forward should be to leverage the value of what already exists – 100 years of commercial aviation experience while finding pragmatic approaches to enable UAS operators to begin BVLOS quickly-he added further.

The Indian Scenario

The Ministry of Civil Aviation replaced the Unmanned Aircraft Systems Rules 2021 last year and although the rules were liberalised, they didn’t open up to BVLOS or “beyond visual line of sight” drone operations.

Before BVLOS operations begin formally, a UTM policy will have to be in place- UTM, an acronym for “Unmanned Traffic Management”- basically an air traffic management system for drones, except that it is an automated tool so that they can communicate while in flight.

Representative | Airosspace

The operating drones must be connected to the internet at all times to ensure that UTMs work accurately. The connection to the internet can happen in three different ways – on a 4G network or an unlicensed 2.4 GHz and 5.8 GHz frequency band.

Some notable BVLOS trials

  • In May of 2021, the Government of Telangana received a conditional exemption for conducting experimental BVLOS drone flights for the delivery of vaccines
  • The National Health Mission, Mumbai, received a conditional exemption for conducting experimental BVLOS drone flights to deliver essential healthcare items in tribal areas of Jawhar in the Palghar district of Maharashtra
  • Led by Throttle Aerospace Systems in collaboration with the Bengaluru-based e-commerce platform Udaan and under the supervision of the DGCA, a BVLOS trial for drone delivery of medicines was successfully completed in Bengaluru ( 20 August 2021)

BVLOS trials will help create a framework for future drone deliveries and other major applications using drones

The Ministry of Civil Aviation

On successful completion of the BVLOS project with regards to safety, security, and viability, the restrictive clauses on these Ops may be lifted.


COVER: Aviation Today