Images Courtesy of Entrol
Flight simulators play a critical role in aviation training, ensuring pilots receive the highest quality instruction in a controlled environment. From the WWII-era instruments-only mechanical simulators to today’s motion platforms with computer-generated visuals of cockpits and landscapes, flight simulators are ever advancing to get as close to the real thing as possible without leaving the ground.
As the quality of graphics has advanced, so has the display technology itself, with virtual reality headsets and projected backgrounds offered as part of several Full Flight Simulator (FFS) systems. But head-mounted devices (HMDs) can be fatiguing, and the multiple projected images required for a wide field of view (FOV) can be finicky to align and maintain, sometimes leading to visual distortions and warping.
Enter Entrol, a Spanish company that designs and manufactures certified flight simulators for fixed-wing aircraft and helicopters. Having produced more than 30 varieties of flight simulators for flight schools and operators in 40 countries, the company was in a unique position—it could envision flight training systems that would achieve the win-win of being both more effective and easier to maintain.
As the quality of graphics has advanced, so has the display technology itself, with virtual reality headsets and projected backgrounds offered as part of several Full Flight Simulator (FFS) systems. But head-mounted devices (HMDs) can be fatiguing, and the multiple projected images required for a wide field of view (FOV) can be finicky to align and maintain, sometimes leading to visual distortions and warping.
Enter Entrol, a Spanish company that designs and manufactures certified flight simulators for fixed-wing aircraft and helicopters. Having produced more than 30 varieties of flight simulators for flight schools and operators in 40 countries, the company was in a unique position—it could envision flight training systems that would achieve the win-win of being both more effective and easier to maintain.
With this goal in mind, Entrol developed ENWALL, the world’s first immersive LED technology designed specifically for pilot training. ENWALL expands the pilot’s FOV and delivers seamless, high-definition visuals without the limitations of HMDs or projectors.
Imagery displayed on ENWALL LED panels is delivered directly to the screens, which offer many advantages over a projection system including higher resolution, better contrast, seamless visuals without distortions, and easier hardware maintenance. The high-quality visuals delivered to ENWALL panels come from ENVISION, Entrol’s customizable image generator, powered by Unreal Engine.
To learn more about ENWALL and how Unreal Engine became an integral part of this groundbreaking solution for flight training, we spoke to Iñigo Hernandez Irizar, Business Development Manager and Head of Communication for Entrol simulators, and Enrique Silvela, Senior Simulation Engineer and Lead Visual Engineer for the ENVISION and ENWALL projects.
Imagery displayed on ENWALL LED panels is delivered directly to the screens, which offer many advantages over a projection system including higher resolution, better contrast, seamless visuals without distortions, and easier hardware maintenance. The high-quality visuals delivered to ENWALL panels come from ENVISION, Entrol’s customizable image generator, powered by Unreal Engine.
To learn more about ENWALL and how Unreal Engine became an integral part of this groundbreaking solution for flight training, we spoke to Iñigo Hernandez Irizar, Business Development Manager and Head of Communication for Entrol simulators, and Enrique Silvela, Senior Simulation Engineer and Lead Visual Engineer for the ENVISION and ENWALL projects.
Images Courtesy of Entrol
Congratulations on your recent launch of ENWALL. Can you tell us more about ENWALL and ENVISION?
Irizar: ENWALL is a modular LED solution that consists of a cylindrical LED blended perfectly with a reinforced floor LED. This solution has been optimized with ENVISION, our Unreal Engine-powered image generator. For us, it was a clear choice to pair LED walls with ENVISION, as we are matching revolutionary hardware with the best possible visual graphics available on the market.
We chose Unreal Engine because of the customization possibilities it provides, allowing us to tailor a customized visual solution to our customers. We were able to customize ENVISION to utilize satellite imagery with a resolution up to one meter per pixel, and high-definition 3D models of airports and heliports made specifically for our customers.
We are also able to create scenarios that cover firefighting, law enforcement, offshore situations, search and rescue (SAR), and emergency medical services (EMS).
Irizar: ENWALL is a modular LED solution that consists of a cylindrical LED blended perfectly with a reinforced floor LED. This solution has been optimized with ENVISION, our Unreal Engine-powered image generator. For us, it was a clear choice to pair LED walls with ENVISION, as we are matching revolutionary hardware with the best possible visual graphics available on the market.
We chose Unreal Engine because of the customization possibilities it provides, allowing us to tailor a customized visual solution to our customers. We were able to customize ENVISION to utilize satellite imagery with a resolution up to one meter per pixel, and high-definition 3D models of airports and heliports made specifically for our customers.
We are also able to create scenarios that cover firefighting, law enforcement, offshore situations, search and rescue (SAR), and emergency medical services (EMS).
Images Courtesy of Entrol
Can you give some examples of how your customers are using ENWALL / ENVISION?
Irizar: ENWALL has been designed with operations training as a pillar. The extended FOV and visual quality ENWALL offers, together with the visual graphics quality ENVISION offers, makes it the best possible combination for operations training.
We have a customer in New Zealand that is installing ENWALL mainly to train air rescue ambulance services. The ENWALL and ENVISION combination is particularly interesting because you can add a realistic accident scene from their database, for example a confined area surrounded by trees. With ENWALL, the pilot is able to position the helicopter above the accident and check the entire scene in the extended FOV. After a simulation of picking up the injured, the helicopter can fly to a high-definition 3D model of the nearest hospital provided by ENVISION, and then use ENWALL to land safely on the heliport.
Another customer in South Korea will also have ENWALL and ENVISION installed to train their firefighting operations. With ENVISION, they can place fire fronts that behave realistically anywhere in the scenario, and water sources can be accessed by helicopter to fill water tanks. After loading the tanks, the operator can extinguish the fires by dropping water on the front. With ENWALL, the firefighters can also check to make sure all the fires are extinguished.
Irizar: ENWALL has been designed with operations training as a pillar. The extended FOV and visual quality ENWALL offers, together with the visual graphics quality ENVISION offers, makes it the best possible combination for operations training.
We have a customer in New Zealand that is installing ENWALL mainly to train air rescue ambulance services. The ENWALL and ENVISION combination is particularly interesting because you can add a realistic accident scene from their database, for example a confined area surrounded by trees. With ENWALL, the pilot is able to position the helicopter above the accident and check the entire scene in the extended FOV. After a simulation of picking up the injured, the helicopter can fly to a high-definition 3D model of the nearest hospital provided by ENVISION, and then use ENWALL to land safely on the heliport.
Another customer in South Korea will also have ENWALL and ENVISION installed to train their firefighting operations. With ENVISION, they can place fire fronts that behave realistically anywhere in the scenario, and water sources can be accessed by helicopter to fill water tanks. After loading the tanks, the operator can extinguish the fires by dropping water on the front. With ENWALL, the firefighters can also check to make sure all the fires are extinguished.
Images Courtesy of Entrol
What are the benefits of using LED screens for simulation rather than using projection?
Irizar: The main benefits are better resolution, and better color contrast. The increased contrast is especially noticeable during night flights, as individual LEDs can turn off completely to create complete darkness, something unachievable with direct projection. You also get seamless visuals, because with LEDs, you get rid of the warping and blending issues that projection can have.
Another benefit is the extended FOV. Because you can add as many LED panels to the solution as needed, the FOV can extend to meet any requirements.
LED panels also offer easier maintenance because the screen is formed from modular panels that are easily interchangeable. The panels are easily accessible and easy to dismount, something that’s especially difficult with projection systems.
The easier maintenance means less downtime for the simulator. While a broken projector brings a training session to a halt, a malfunctioning LED panel does not. As each panel is formed of many individual small LEDs, if a single LED fails, the training can still continue. When a significant group of these LEDS breaks, something extremely rare, you can easily replace that one module, and even perform the replacement during an ongoing training session without interrupting it.
Irizar: The main benefits are better resolution, and better color contrast. The increased contrast is especially noticeable during night flights, as individual LEDs can turn off completely to create complete darkness, something unachievable with direct projection. You also get seamless visuals, because with LEDs, you get rid of the warping and blending issues that projection can have.
Another benefit is the extended FOV. Because you can add as many LED panels to the solution as needed, the FOV can extend to meet any requirements.
LED panels also offer easier maintenance because the screen is formed from modular panels that are easily interchangeable. The panels are easily accessible and easy to dismount, something that’s especially difficult with projection systems.
The easier maintenance means less downtime for the simulator. While a broken projector brings a training session to a halt, a malfunctioning LED panel does not. As each panel is formed of many individual small LEDs, if a single LED fails, the training can still continue. When a significant group of these LEDS breaks, something extremely rare, you can easily replace that one module, and even perform the replacement during an ongoing training session without interrupting it.
Images Courtesy of Entrol
What are the biggest learnings you’ve experienced while developing ENWALL?
Silvela: One of the most significant lessons came early on when we developed our first LED display using a spherical configuration, similar to traditional projector setups. Spherical displays offer a much wider field of view compared to cylindrical ones, which seemed ideal at first. However, during testing, we discovered several issues.
Because perfect pixel-to-surface mapping isn't possible on a sphere, we had to remove some pixels to achieve the curved shape. While this wasn't noticeable in standard video playback, it introduced serious issues during simulator use. For instance, distant trees, which only occupied a few pixels on the screen, would intermittently flicker or disappear, distracting pilots during flight.
Maintenance was another challenge. Spherical LED setups involve complex, non-standard panels that are harder to service and replace. In contrast, cylindrical displays allow for a clean grid-to-surface pixel mapping with no pixel loss or flickering. Plus, their uniform panel design significantly simplifies maintenance.
The trade-off, however, was vertical field of view (VFOV). Helicopter pilots, in particular, require a high VFOV to see through the chin window, and cylindrical displays don’t naturally support this as well as spherical ones.
That’s when we had a breakthrough idea: instead of sticking to a single, continuous and complex display surface, we could split the visuals across different simpler geometries. By keeping the cylindrical display and adding a flat LED floor beneath the cockpit, we significantly increased VFOV without sacrificing pixel integrity or maintainability. This modular solution ultimately proved more effective than a spherical setup in every way.
Silvela: One of the most significant lessons came early on when we developed our first LED display using a spherical configuration, similar to traditional projector setups. Spherical displays offer a much wider field of view compared to cylindrical ones, which seemed ideal at first. However, during testing, we discovered several issues.
Because perfect pixel-to-surface mapping isn't possible on a sphere, we had to remove some pixels to achieve the curved shape. While this wasn't noticeable in standard video playback, it introduced serious issues during simulator use. For instance, distant trees, which only occupied a few pixels on the screen, would intermittently flicker or disappear, distracting pilots during flight.
Maintenance was another challenge. Spherical LED setups involve complex, non-standard panels that are harder to service and replace. In contrast, cylindrical displays allow for a clean grid-to-surface pixel mapping with no pixel loss or flickering. Plus, their uniform panel design significantly simplifies maintenance.
The trade-off, however, was vertical field of view (VFOV). Helicopter pilots, in particular, require a high VFOV to see through the chin window, and cylindrical displays don’t naturally support this as well as spherical ones.
That’s when we had a breakthrough idea: instead of sticking to a single, continuous and complex display surface, we could split the visuals across different simpler geometries. By keeping the cylindrical display and adding a flat LED floor beneath the cockpit, we significantly increased VFOV without sacrificing pixel integrity or maintainability. This modular solution ultimately proved more effective than a spherical setup in every way.
Images Courtesy of Entrol
Why is visual fidelity and accuracy so important for this type of simulator?
Irizar: Visual fidelity and accuracy are key players in flight simulators. A simulator that does not meet the visual accuracy standards fails to provide the required immersion for the trainees, and the realism required to train on operations efficiently.
Immersion is key, since the aim of flight simulators is to provide a training experience as close as possible to reality. If the visual quality of the simulator does not achieve this standard for reality, the pilot can get distracted. It decreases immersion, which decreases the quality of training.
Realism of operations is also extremely important. The operations need to feel as real as possible for the training to be effective, and this can only be achieved with high visual fidelity and accuracy. For example, while training SAR in a mountain area, the pilots need to be able to recognize their surroundings and landmarks, something that can only be achieved with high-quality visuals.
Irizar: Visual fidelity and accuracy are key players in flight simulators. A simulator that does not meet the visual accuracy standards fails to provide the required immersion for the trainees, and the realism required to train on operations efficiently.
Immersion is key, since the aim of flight simulators is to provide a training experience as close as possible to reality. If the visual quality of the simulator does not achieve this standard for reality, the pilot can get distracted. It decreases immersion, which decreases the quality of training.
Realism of operations is also extremely important. The operations need to feel as real as possible for the training to be effective, and this can only be achieved with high visual fidelity and accuracy. For example, while training SAR in a mountain area, the pilots need to be able to recognize their surroundings and landmarks, something that can only be achieved with high-quality visuals.
Images Courtesy of Entrol
What makes Unreal Engine the right choice for rendering the visuals for ENWALL?
Silvela: Given that our display surface is well-defined, we leveraged nDisplay to warp the camera frustum accurately for both the curved cylindrical screen and the floor display.
This meant we didn’t need to rely on external warping software, which greatly streamlined the installation process and reduced complexity.
It also allowed for a seamless visual transition between display surfaces. By defining a single pilot head position as the reference, nDisplay automatically handled frustum adjustments to maintain visual continuity across the entire display. The result is an immersive, distortion-free experience from the pilot’s point of view.
Irizar: With the implementation of ENVISION, we made a giant leap forward from our previous image generator. The visual quality has improved with this change, but it has not been the only improvement.
Unreal Engine also allows us to easily customize the terrain and features we include in our simulator, which means we can build a solution tailored to our customer’s training requirements.
This has helped us reduce manufacturing costs while improving the final product delivered.
Unreal Engine has been a great success for us in every possible way.
Silvela: Given that our display surface is well-defined, we leveraged nDisplay to warp the camera frustum accurately for both the curved cylindrical screen and the floor display.
This meant we didn’t need to rely on external warping software, which greatly streamlined the installation process and reduced complexity.
It also allowed for a seamless visual transition between display surfaces. By defining a single pilot head position as the reference, nDisplay automatically handled frustum adjustments to maintain visual continuity across the entire display. The result is an immersive, distortion-free experience from the pilot’s point of view.
Irizar: With the implementation of ENVISION, we made a giant leap forward from our previous image generator. The visual quality has improved with this change, but it has not been the only improvement.
Unreal Engine also allows us to easily customize the terrain and features we include in our simulator, which means we can build a solution tailored to our customer’s training requirements.
This has helped us reduce manufacturing costs while improving the final product delivered.
Unreal Engine has been a great success for us in every possible way.
Images Courtesy of Entrol
How have your solutions developed over time, and what influence has Unreal Engine had on that?
Silvela: We began development on ENVISION three years ago using Unreal Engine 4.26. At the time, we were constrained by engine limitations around world size and data handling, so we had to devise clever workarounds to keep our simulation performant.
The release of Unreal Engine 5 marked a major turning point. Features like Large World Coordinates, World Partition, and Nanite enabled us to dramatically scale up our databases without sacrificing performance. With those constraints lifted, we shifted focus to enhancing visuals, realism, and system architecture.
Over time, ENVISION has evolved from a basic prototype running on a single machine to a robust image generator operating in sync across multiple PCs.
Working with Unreal has been a rewarding journey. While the engine is complex, its capabilities are unmatched, and mastering it has significantly elevated our project.
Silvela: We began development on ENVISION three years ago using Unreal Engine 4.26. At the time, we were constrained by engine limitations around world size and data handling, so we had to devise clever workarounds to keep our simulation performant.
The release of Unreal Engine 5 marked a major turning point. Features like Large World Coordinates, World Partition, and Nanite enabled us to dramatically scale up our databases without sacrificing performance. With those constraints lifted, we shifted focus to enhancing visuals, realism, and system architecture.
Over time, ENVISION has evolved from a basic prototype running on a single machine to a robust image generator operating in sync across multiple PCs.
Working with Unreal has been a rewarding journey. While the engine is complex, its capabilities are unmatched, and mastering it has significantly elevated our project.
Images Courtesy of Entrol
How do you use Unreal-based workflows in your planning or design phases?
Silvela: Our workflow covers everything, from sourcing geographic data to modeling geospecific environments. We've developed custom asset importers that allow us to work directly with GIS data inside Unreal Engine. This significantly streamlines the database creation process, enabling us to populate vast terrain areas using widely available sources like OpenStreetMap (OSM).
Silvela: Our workflow covers everything, from sourcing geographic data to modeling geospecific environments. We've developed custom asset importers that allow us to work directly with GIS data inside Unreal Engine. This significantly streamlines the database creation process, enabling us to populate vast terrain areas using widely available sources like OpenStreetMap (OSM).
Images Courtesy of Entrol
Finally, what do you think the future of flight simulations looks like? What can we expect from Entrol in the future?
Irizar: The future of simulators looks bright. Technology is advancing at a high pace, with disruptive technologies entering the market.
Entrol is currently focusing on developing affordable FFS Level B devices. The market prices of these kinds of devices have been around €10 million for the last two decades, and we want to tackle that. Our goal is to be able to offer reliable, top-quality FFS Level B devices for around €6-7 million.
So from Entrol, you can expect more exciting news about sales and developments in the coming years.
Irizar: The future of simulators looks bright. Technology is advancing at a high pace, with disruptive technologies entering the market.
Entrol is currently focusing on developing affordable FFS Level B devices. The market prices of these kinds of devices have been around €10 million for the last two decades, and we want to tackle that. Our goal is to be able to offer reliable, top-quality FFS Level B devices for around €6-7 million.
So from Entrol, you can expect more exciting news about sales and developments in the coming years.
How to install Unreal Engine
Download the launcher
Before you can install and run Unreal Editor, you’ll need to download and install the Epic Games launcher.
Install Epic Games launcher
Once downloaded and installed, open the launcher and create or log in to your Epic Games account.
Get support, or restart your Epic Games launcher download in Step 1.
Install Unreal Engine
Once logged in, navigate to the Unreal Engine tab and click the Install button to download the most recent version.
Watch how to install