How UT drone inspections elevate safety and efficiency in NDT


Explore how the integration of ultrasonic testing (UT) capabilities with aerial drone solutions is transforming non-destructive testing (NDT) across industries that include maritime, oil and gas, and power generation. 

In recent years, integrating UT capabilities with aerial drone solutions has transformed NDT inspections across oil and gas, power gen, and maritime industries. By offering a safer and more efficient alternative to traditional inspection methods, UT drone inspections are revolutionizing the way asset owners and inspection service providers (ISPs) conduct NDT inspections.

The challenges of traditional UT inspections

Common non-destructive testing (NDT) inspection methods require the inspector to be within arm's reach of the data collection point. However, some sections of the assets being surveyed may be challenging to access. In large assets such as ballast tanks, stacks, or pipe racks, inspectors often have to rely on mobile elevated work platforms (MEWPs), rope access, or scaffolding to reach the measurement site. Those traditional methods prove to be slow, costly, and often pose safety risks associated with working at height or in confined spaces. 

The benefits of UT drone inspections 

Drones provide NDT experts with a unique aerial perspective, enabling quick access to remote or inaccessible areas without compromising the pilot’s safety. Aerial solutions, when equipped with UT capabilities, give non-destructive testing professionals a fast and accurate means of performing inspections while reducing operational costs and minimizing safety risks.

Here are some of the main advantages of using UT drone inspections:

  • Drones reduce operational costs by replacing traditional NDT methods and decreasing labor and equipment expenses.
  • Drones can cover large areas faster than human operatives, optimizing operational efficiency and minimizing downtimes.
  • Drones can be equipped with a variety of sensors and cameras to adapt to diverse inspection needs offering a flexible and adaptable solution for a wide range of inspection scenarios.
  • Drones enhance safety by removing the need for scaffolding and work at height entirely.
  • Drones can precisely cover all areas of a structure, reaching remote, hazardous, or otherwise inaccessible areas with ease.
  • Drones aid in monitoring the structural integrity of materials and can provide emergency assistance in the event of an incident.
  • UT surveys performed with drones are faster and provide objective and accurate data allowing for informed decision-making and operational improvements. 

The Elios 3, a drone designed to perform ultrasonic inspections in hard-to-reach areas

The Elios 3 is a unique drone engineered to remotely collect data in tight and difficult-to-access areas, prioritizing human safety. It is widely utilized by visual inspection teams around the world to service assets in industries that include oil and gas, maritime, power generation, cement, and many more. With its onboard visual inspection payload and modular design, the drone can seamlessly adapt to carrying 2 additional payloads according to the needs of the project.  

The Elios 3 drone with the UT payload mounted, including couplant dispensor 

With the UT payload mounted, the Elios 3 turns into a flying UTM gauge performing both visual and material thickness inspections. Developed in collaboration with UT specialists Cygnus Instruments, the UT Payload features an articulated arm that can be molded according to the shape of the inspection area. A built-in laser pointer enables the pilot to perfectly position the probe head onto the target area. Magnets on the probe head help it affix to the test surface, and there are 3 different probe heads (2Mhz, 5Mhz, and 7.5Mhz), each one suited to measuring heavily corroded metals and featuring an Echo-Echo mode to measure through up to 1 mm (0.040 inches) of surface coating.

To ensure clear results in hard-to-reach areas, the Elios 3 offers two additional features:

  • A couplant dispenser designed to be operated beyond visual line of sight. This dispenser guarantees that the whole surface between the probe and the material under test is properly lubricated, letting ultrasound pass through the material and ensuring UT measurements are taken correctly.
  • A cleaning module that can be mounted to prepare the test surface in case dust or dirt is in the way.

Unlike other drones on the market, the Elios 3 is optimal for use as a UT drone inspection tool because it is specifically tailored for surface-contact inspections, making it exceptionally suitable for UT inspections. Its compact size and patented reversing motor technology enable the drone to effortlessly navigate cluttered spaces and pass through openings as small as 50 x 50 cm (20 x 20 inches), all while maintaining stable flight.

Example applications for UT drone inspections

With a proven track record across multiple industries, the Elios 3 and the UT payload, can be used in:

  • Ship inspections → Conducting UTM and visual inspections on a cargo ship is a monumental task. The process is costly and slow. The Elios 3 offers a better way; it removes the need for scaffolding entirely and conducts UT scans faster than a human operative without compromising on accuracy. Flyability’s proprietary software saves scan locations in a 3D model of the asset, providing precise location tagging for repeated measurements.
  • Stacks → Industrial stacks are critical pieces of infrastructure. Traditionally, inspections involve using rope access and boom lifts to carry the UT inspector to various points across the chimney, slowly assessing hundreds of test points manually over multiple days. The stack must be shut down for the duration of the job which causes economic losses due to prolonged downtime. The Elios 3 can save time and money by conducting the inspection remotely, cutting on the staging and inspection costs while speeding up the entire process.
  • Steel storage tanks → Scaffolding is often the most effective way to bring workers to UT measurement points at height, but it is also a slow and expensive process. If there are 40-60 inspection points in a storage tank, there is often no choice but to spend tens of thousands of dollars to erect scaffolding. By using the Elios 3 for a UT drone inspection, inspectors can improve operational and cost efficiency while keeping workers safe on the ground. The drone can fit through manholes to gather ultrasonic thickness measurements and close-up visual surveys in minutes.
  • Pipe inspections → Process piping stands as a key component within the infrastructure of any processing plant. These pipes serve as conduits for a diverse range of substances, ranging from acids and alkalis to hot and cold fluids, with some being toxic. Maintaining their structural integrity is paramount. The Elios 3 is the only drone solution that can easily fly through the intricate spaces between pipes for measurement gathering. Its articulated probe arm allows the probe to reach almost any inspection point regardless of the geometry of the space, securing systematic accurate results.

An Elios 3 being prepared for a UT drone inspection inside a steel tank

UT drone inspection procedure

The operational process of the Elios 3 drone comprises three primary stages: 

1. Upstream work and planning 

The upstream phase involves defining mission objectives, identifying the inspection area, assessing risks, obtaining permissions, securing equipment, and assembling the team. 

Once completed, the planning phase begins, involving flight path planning, scheduling, logistics coordination, and considering factors such as weather and airspace regulations. Addressing these aspects diligently ensures efficient and safe drone missions, delivering valuable data for inspection and analysis.

2. The UT drone inspection flight

Typically, an ultrasonic drone inspection is done by a team of two people: a drone pilot and a UT-certified inspector. The pilot collaborates closely with the inspector during the inspection process, ensuring all necessary data is acquired. 

The Elios 3 completing a UT drone inspection inside a tank

Before entering the asset, the pilot adjusts the articulated probe arm to a position suited for the mission. Next, they fly and navigate the drone to each measurement point, systematically collecting measurements. A built-in laser pointer enables the pilot to perfectly position the probe head onto the target area. Upon reaching a measurement point, the pilot can release the couplant by pressing a button on the remote controller. The A-scan data is displayed on the tablet for immediate assessment of the measurement quality.

At this point, and only if necessary, the UT inspector can manually adjust gain and gates to refine the A-scan until they get a clean measurement.

The Cockpit interface showing the gain and gates being adjusted in flight

In case the surface under test is too corroded or covered with some dust/debris that prevents the probe from functioning properly, the cleaning module can be mounted in place of the probe to prepare the surface for measurement. The pilot will mark the location as clean with a point of interest in Cockpit so they can easily guide the drone back to the same location once equipped with the cleaning module.

3. Downstream work & reporting 

After the mission, all the data is downloaded into Inspector 5, the companion software for the Elios 3. Within the software interface, all flight data points are visualized and mapped onto a digital twin of the asset, facilitating rapid review. Each measurement can be validated and fine-tuned by re-selecting the most relevant echo signals. 

The Inspector 5 interface shows the UT measurements within a 3D model 

These data points can be documented with assigned criticality levels and descriptions before being incorporated into reports, which also include calibration data proving that the equipment was properly calibrated prior to performing the measurement survey.

The Future of ultrasonic drone inspections with the Elios 3 

The Elios 3 and its UT payload are perfectly positioned to bring a revolution to NDT. This tool empowers safer operations while reducing the time and costs associated with a challenging ultrasonic thickness measurement. The drone pilot and UT inspector can fine-tune their flights and UT measurements according to the needs of each asset, reproducing the process for routine inspections as necessary with a high degree of accuracy. The Elios 3 also empowers greater data coverage, gathering LiDAR, visual, and UT data simultaneously. Whether the Elios 3 UT is deployed to inspect a ship’s hull or the inside of a stack, the walls of a tank or a pipe network, it is ready to simplify non-destructive testing across industries.

Find out more about the Elios 3 UT Payload

For further details about the Elios 3 UT Payload and how it could revolutionize your operational efficiency, reach out to us. Our team of experts is here to assist you at any stage of your drone adoption journey.

Talk to our team about UT drone inspection with the Elios 3


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