The 7 Major Benefits of Indoor Drones for NDT in Internal Inspections

Drones present several benefits as a tool for remote visual data collection in NDT (Non-Destructive Testing) indoor inspection scenarios—here is our list of the top 7.

Inspectors working in Non-Destructive Testing (NDT) these days use a range of tools to collect data remotely.

These tools are generally referred to as RVI (Remote Visual Inspection), a name that signifies the ability to collect information from a distance. 

Usually the information inspectors collect is visual data—that is, pictures and video showing the condition of key parts of an asset, with the goal of identifying potential defects that may require further investigation or even maintenance. 


An RVI tool could be something as sophisticated as Flyability’s Elios 2 drone (shown above) for indoor inspections, or it could just be a camera hanging from a piece of rope. 

Either way, the goal of using RVI in an indoor inspection (i.e., for a boiler, pressure vessel, chimney, or some other asset that requires entry) is to give inspectors a way to collect data inside an asset without having to put themselves in harm’s way by entering it or having to stand on scaffolding inside of it.

Of all the RVI tools available to inspectors, indoor drones provide several benefits for NDT—keep reading for our list of the top seven.

What Is NDT?

NDT (Non-Destructive Testing) refers to an array of inspection techniques that allow inspectors to collect data about an asset or material without damaging it.

Visual data is the most common kind of data collected in NDT, but inspectors may use other NDT testing methods in addition to visual testing, like ultrasonic testing or radiography testing.

The 7 Major Benefits of Indoor Drones for NDT in Indoor Inspections

1. Improved Safety

Indoor inspection scenarios present three primary hazards to inspectors: 

  • Falling 
  • Being trapped
  • Being exposed to potentially harmful gases

In addition to these three, a few industries have their own unique hazards. 

For instance, grain bin inspections present a hazard from the grain itself, which can drown a person if they fall into it.

Regardless of the specific use case, all of the hazards presented to inspectors by entering a confined space can be eliminated with the use of a drone.

The reason inspectors enter a confined space is to collect visual data—but new indoor inspection drones like the Elios 2 can completely replace the inspector, collecting visual data remotely that is of such high quality the inspector does not need to enter the confined space at all.

And by eliminating the hazards associated with entering a confined space, the drone dramatically improves safety for the inspection.

[Related reading: The Hierarchy of Control for Indoor Inspections—And Where Drones Fit In]

2. ROI & Savings

Using a drone for visual NDT instead of a person can save companies huge amounts of money.

Here are the primary ways companies save by using indoor drones for inspections:

  • No scaffolding needed. Temporary structures like scaffolding that are used for inspections can be incredibly expensive to put in and take out, sometimes costing tens or even hundreds of thousands of dollars for a single inspection. Using a drone eliminates the need for scaffolding, which represents huge potential savings for companies.
  • Reduced downtimes. Because installing and taking down scaffolding is so time consuming, using a drone can also mean significantly shorter turnaround times, lessening the loss of potential revenue from having assets offline.
  • Less liability insurance needed. Because using a drone is safer than sending a person into a confined space, some companies have been able to reduce their premiums for liability insurance by using drones for indoor inspections.

Here are some case studies highlighting the savings that an indoor drone can make possible:


3. Increased Frequency of Inspections

Because drones are a relatively inexpensive solution for Visual Non-Destructive Testing, companies can use them to increase the number of inspections performed over time while still realizing significant savings.

Increasing inspections can help increase the longevity of a company’s assets by revealing defects earlier in the maintenance cycle, and fixing them before they grow worse. 

Increasing inspections by using drones can also help companies be more environmentally friendly. A recent study conducted by Boiler Room Consulting found that using drones to inspect boilers could help reduce CO2 emissions by as much as 649 metric tons a year.

4. Data Localization

If you have to dig into a sewer system to fix a defect found during an inspection flight, or cut into a pipe, locational accuracy is incredibly important.

Flyability’s new Inspector 3.0 software allows inspectors to pinpoint the location of defects, giving them a sparse point cloud that shows them exactly where every defect found in an inspection flight is located.

The data localization provided by Inspector 3.0 is enabled through drone technology, and it can significantly improve the inspection process by providing a quick way for all parties involved in the maintenance process—the inspector, the maintenance crew, site managers, and other stakeholders—quick insights into where work might need to be done.

5. Providing a Historical Record

While manual inspections may only produce video and still images of potential defects found during the visual inspection, a drone flight shows all parts of the asset filmed during the mission.

This visual data provides a historical record of the condition of the asset at a given point in time. Further, visual data can be turned into 3D models and/or point clouds (the latter is supported by Inspector 3.0, as covered above), which can contain even more details about the condition of an asset at a moment in time.

All of this data could be helpful for investigating the causes of an accident, or simply to track the evolution of a defect’s development. 

Drones enable this detailed record keeping, providing companies with a robust historical record of the history of their key assets.

6. Improved Access within Assets

In some instances, manned entry simply cannot provide access to key parts of an asset—but an indoor drone like the Elios 2 can often reach these areas. 

Here are some examples:

Sewer inspections

Some sewer systems contain gases that are dangerous to people, or water running at a volume that is too high for a person to safely enter. 

If the diameter of the pipe is wide enough, a drone can enter and safely record visual data from a distance, providing access that wouldn’t be possible for a person. These challenges can limit manned entry for sewer inspections, and in some cases can prevent a full visual inspection of the entire sewer system.

Wind Turbine Inspections

Inspectors are often limited in how far they can enter a wind turbine to inspect its blades, both by the physical possibility for entry and by law.

But a drone can fly beyond these limitations, providing inspectors with more data on the conditions of the blades inside their turbines than would be possible to collect using manual methods.

Watch this video to learn about how the Elios 2 allowed inspectors to get 60% more access to the blades in a wind turbine during an inspection:

Bridge inspections

Some bridges contain spaces that are difficult for inspectors to access, such as tight areas between beams and box girders. These tight spaces can make bridge inspections challenging for manned entry, and in some cases can prevent a full visual inspection of the entire bridge.


In both of the inspection scenarios listed above, a caged indoor drone like the Elios 2 can provide inspectors access to tight, confined spaces for the purposes of visual data collection—spaces that couldn’t be accessed at all without a drone. 

7. Higher Quality Data

Because modern drone technology provides a visual record of an inspection in the form of a video, inspectors can save the outputs from a flight and refer to it later to monitor changes to assets over time. 

New software created to process drone data can help provide accurate measurements within this visual data, leading to the capture of better data and a more thorough historic record of the life of an asset, which can be referred to at any time.



Wondering how Inspector 3.0 differs from other 3D modeling software? Read this article to find out.


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