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Remotely-operated control towers

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Pilots and airport operations could benefit from the enhanced safety of ATC services without an at-airport physical tower.


A supervisor’s view over 2 remote air traffic controller stations and the accompanying camera-fed display of a distant airport.
By Glenn Woodward
Contributing Writer

January of 2018. The pilot of a Beechraft Bonanza on final to Rwy 33 at FNL (Fort Collins/Loveland CO) failed to understand a series of UniCom messages from a helicopter pilot practicing an instrument approach to a “missed” that was descending to the approach end of the runway.

The airplane pilot reported that he was passing overhead to a full-stop landing. The situation did not end well. The Bonanza struck and destroyed the helo, and left the runway after touching down. Luckily, no one died, but this situation was completely avoidable.

There were no terminal ATC services in place at the time of the accident, and a control tower for an airport this size costs about $3 million – assuming the airport would even qualify for such a facility.

It’s easy to say, after the fact, that it would have been worth it, but revenue streams, politics, and expenditures are conjoined triplets whose connecting points vary from moment to moment.

Add government bureaucracy and the excruciatingly long time it takes for projects to be completed, and you have a continuing safety risk – basically, standard operating procedures for uncontrolled airports.

The fix

A remotely-operated tower (ROT) could have prevented that accident. It is a visually-based, radar/artificial intelligence (AI)-augmented ATC facility where 1 controller handles 1, or several, airports simultaneously from an off-site location called a remote tower center (RTC).

One or more airport authorities can sidestep the red tape and delays of government-administered ventures, and do so effectively by sharing the cost among various stakeholders. In the case of FNL, the airport formed a coalition to fund its ROT project that included the Colorado DOT’s Aeronautics Division.

The ROT concept does not necessarily replace ATC control towers. Instead, it adds a layer of safety and/or cost efficiency where there was none before. It is also an alternative means of securing ATC services in lieu of a brick-and-mortar tower that requires a complicated funding maze.

In other words, airports that do not – nor would ever – qualify for a tower facility can now enjoy an umbrella of ATC services, safety, and other associated benefits. At FNL, this safety factor alone has encouraged Allegiant Airlines to reinstate scheduled service to the airport.

In Norway and Sweden, the 13-year SESAR project has resulted in a facility that can handle up to 3 airports simultaneously with 1 or 2 controllers. Remote airports in Scandinavia are realizing the benefits of ROTs.

Combining resources dilutes the cost of bringing ATC services to their towns by 50% or more, and enhances the safety of the flying environment. Sweden has even gone so far as to design and construct an airport on the northern border with Norway served by a remote tower and catering to winter sports traffic.

ROTs have a twofold effect – they bring the safety umbrella ATC provides, and pose an opportunity to increase the connectivity of small airports and their related local commerce to the outside world.

Remote visualization

Imagine a soundproof room that has a camera-fed 360º view of a small airport 300 miles away, displayed on a set of screens for a certified air traffic controller who has full view of the airport and its surrounding airspace.

This view is nearly identical to the one in a control tower at that airport (should it ever exist), and it’s augmented with radar and AI upgrades. From the center of the room, the controller can see each aircraft along with a data block similar to one displayed in an approach or air route traffic control center.

The cameras can zoom in on an object to show abnormalities which are not visible to the naked eye, along with decision-assistance such as lists of prioritized options for further control instructions.

Wearing a special set of glasses, the controller selects from that list with a movement of their hands or eyes “layering” their response actions, saving time and, perhaps, lives. If the situation is such that a call to the airport fire department is necessary, preselected data can transmit automatically to rescue agencies via synthetic voice and encrypted text.

Now imagine this same controller in a slightly larger room with 3 rows of projector-screens – side-by-side or stacked – offering the same view for completely different airports hundreds of miles away. And just to make things interesting, the room is now a warehouse, and the controller is responsible for up to 3 different airports – all visible simultaneously.

Using a special pair of glasses, a controller could freeze an image to send to maintenance or a supervisor, along with the data block and other necessary information, while still remaining available to control other aircraft and airports.

Multiple controllers monitor simultaneously-displayed views of a complex facility or multiple airports.

Remote tower technology

This technology is currently in the final testing and validation stages in the US and EU. At FNL, a state-of-the-art facility is soon to be validated by FAA, while Europe is in the final validation stage of a multi-airport remote tower module (RTM).

While the reasons and justifications are numerous, Sweden is years ahead in terms of implementing a functional ROT. The Swedish facility began live operations in 2015, and is soon to be expanded to an RTC within which RTMs operate.

Think of a radar center where a supervisor monitors several controllers handling aircraft in adjoining airspace sectors, while other supervisors monitor similar groupings of controllers handling other clusters of airspace. The difference is a radar data display versus an aggressively augmented visual display.

RTCs work in the same manner, where a supervisor monitors 1 (or several) RTMs with 1 or 2 controllers handling multiple airports simultaneously. The idea boils down to economies of scale. Traditionally, where 1 controller handles aircraft at 1 airport, the underlying costs associated with that controller are pigeonholed and cannot be used as efficiently.

Previously, downtimes between aircraft were wasted waiting for the next airplane or vehicle to call, but now, the same controller and skill sets handle multiple aircraft and vehicles at several airports safely and efficiently.

While airports exist throughout the world that are not especially busy but still need a controller and other associated aviation infrastructure – such as meteorological services or flight information services – consolidating those assets into one structure and entity will save hundreds of millions of dollars.

ATC services, including controllers, weather observers, and flight information services specialists, can now be applied equally across many airports from one central location – an RTC. Cost savings in human resources (HR) are tremendous.

One set of specialists with one HR benefit cost package diluted across several airport funding pools has a twofold effect. The first obvious effect is the drastic lowering of direct costs to an airport, but it also offers service providers the opportunity to attract, solicit, and entice a higher caliber of specialist with better pay and benefits.

Compensation packages should be elevated commensurate with the exponential increase in individual responsibilities and liabilities. In the US, ATC union officials are adamant about “1 controller, 1 airport,” and the reasoning has to do with volume and complexity.

In Europe, where there are fewer GA airports and, consequently, lower traffic volume, 1 controller handling multiple airports makes more sense. Cost benefits aside, improved safety, and all the stakeholders are beneficiaries.

Safety is increased with high-quality visual media and advanced radar technologies, managed by a human controller and augmented through the application of AI.

Cameras at JYO (Executive, Leesburg VA) tower provide a 360° image display of the airport’s runway, ramps, and surrounding airspace.

Back to the action

Inside a tower cab, many sensory inputs exist that allow a controller to respond and react efficiently when required.

This is commonly referred to as situational awareness (SA), and it’s a crucial aspect of a controller’s training. Hearing is a very important aspect of SA, and one I had not seen heavily addressed in my research.

Those aural filters, learned through experience, are very special skills, and training a microphone to discern “generic” over “life threatening” inputs presents a unique technological and managerial challenge. Another parallel aspect of this audibility component is the time it takes for communications to occur.

The delay could be up to 1 second. In my experience, 1 second has often been the difference between safe and unsafe. It’s like watching an interview on TV where there is a delay in the audio feed, and people end up talking over each.

To me, even in the worst-case scenario of a 1-second delay, the Bonanza and the helicopter would not have collided at FNL. One question often asked is “Would a person fly on an airplane that doesn’t have a human pilot on board?” I have often received a resounding “no” in response to that question.

But an appropriately similar query concerning aircraft operating at an airport without a human controller in the tower would likely receive a different answer, because pilots train regularly to fly in and out of airports defined as uncontrolled.

In situations where there has been neither loss of life nor an aircraft accident, but many close calls or near-misses, ROTs reinsert the human factor into the equation. This human link completes the safety system via skills and processes.

In that same vein, controllers must train to handle multiple facilities at the same time, with different types of aircraft in uniquely different flying environments.

On the ground

Remote tower operations are not just for aircraft in flight. AI, augmented vision, and predictive analytics can detect a multitude of processes in play for aircraft taxiing and at the gate. Current technology can detect the proper number of safety cones and their correct placement.

In addition, with zoom technology, security is enhanced using facial recognition or other body physiologies. Integrated with special sensors, the pace of ground personnel can be monitored for safety and efficiency.

Did a bag fall off the luggage cart? Was catering on time, or late? All of these metrics are monitored visually and matched with a process to discern completion or identification of improvement potential. Although these may be ramp controller duties, missed pitot tube covers, venting fuel, excess oil leakage, and open access or cargo doors could be caught on the ground by the controller before the aircraft takes off.

Add in a sensitive thermal imager, and a controller can detect a potential hot brakes situation well in advance to notify the authorities.

But what if…?

In an emergency, the RTC watch supervisor has the ability and authority to reassign an airport to a different RTM, leaving the controller to focus wholly on the critical situation without distraction.

Safety, again, comes first with backup systems in place for contingencies, such as loss of cameras or loss of communications. These are addressed via built-in redundancies. If the augmentation drops offline, the controller falls back to standard air traffic skill sets for spacing and sequencing.

This could lead to an additional branch of training that is currently split into just 2 specialties – tower/radar – further dividing the “tower” branch into “facility or ROT.” Other effects include more stringent vetting for ATC candidates, longer and more complex training, and the peripheral infrastructure resources necessary to support the training dynamics.

Looking further ahead

The augmented ROT could also display the projected route off the end of the runway, and alert the aircraft and pilot to traffic, terrain, or other potential conflicts. Now imagine 2 or 3 more camera towers that can integrate their data to a holographic projection instead of a 2-dimensional display.

This portends an interactive environment between the controller and the pilot, where the controller “grabs” the aircraft and moves its desired destination (on a SID or a STAR). After approval from the pilot, the aircraft would then fly on autopilot via the most efficient or expedient route.

With built-in safeguards and the option for the pilot to decline the route or performance parameters, fuel and time are saved while guaranteeing a safety net. And let’s not forget an overlay of weather and winds at altitude available to the controller.

This would maximize airspace utilization efficiency, which, again, translates into money saved. The weather and wind input would come from specialized airport drones using swarm-technology as well as built-in buffer technology, operating under the control of the airport authority/FAA and providing real-time met data.

A new way to control air traffic

The remote tower concept is but a small taste of a cornucopia of potential technology applications that streamline and polish ATC in the cab. It is more than just a way of multiplying the 2 points of contact between controller and aircraft.

It is amplifying and supplementing those 2 points efficiently, creating a symbiotic connection that enhances safety and service to a level not currently provided. I for one am excited about the future of remote ATC. Somebody hand me a headset!


Glenn Woodward is an air traffic controller with 18 years of tower experience in the US, UK, and Afghanistan. He is an FAA-licensed flight dispatcher as well as a veteran flightcrew member on Boeing B-52s.