UT Payload - Quick Start Guide

Discover everything you need to know to get started with your Elios 3 UT Payload



  1. Before starting
  2. Updating your Elios 3 and Inspector 5
  3. Mounting the UT payload on the Elios 3
  4. Available training
  5. Disclaimers
  6. Getting ready for your first flight
  7. Your first flight
  8. Problems you may encounter during a UT flight
  9. How to use the Elios 3 UT cleaning module
  10. Maintenance and care
  11. Support and contact information
  12. Resources


Before Starting 

Unboxing the payload

When you have received your new UT Payload, make sure that the package is not damaged externally. If any substantial damage can be seen on the package, contact our customer support team (support@flyability.com) before opening it. Although it is protected, please do not use something sharp that could damage the payload while opening the package. 

Remove the UT Payload from the package and conduct a first visual inspection of the product. If any items from the list above are missing or seem damaged please contact us at support@flyability.com.

Software requirements

To smoothly download and work on Inspector 5 with the data captured from the UT Payload we suggest that you have a Desktop PC that matches the following requirements (or above):



Windows 11 64-bit

Windows 11 64-bit

Intel Core i5-1135 or AMD equivalent

i7-8750H @2.20GHz (6 cores)


16+ GB RAM

Iris Xe Graphics (Minimum tested)

Nvidia GTX 1050 or AMD RX 560 

30 GB Storage

250+ GB Storage


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Updating your Elios 3 and Inspector 5

To operate the UT Payload you will need the 2024.02 update for the E3 onboard software, Cockpit and Inspector, or any later update. See here all the information about the Elios 3 system updates.

To install the updates, you should open Inspector with your computer connected to the Internet, where you will be prompted by a pop-up to upgrade (see below) or you can download the new Inspector 5 software here.

1.1 Pop-up update

Select update and wait for Inspector 5 to install. Inspector 5 will download as a separate software from Inspector 4 so both versions will remain available to you.

Please find more info on how to move from Inspector 4 to Inspector 5 here.

Once installed, launch Inspector 5 and connect your Elios 3 to your PC. Inspector will prompt you to update your drone. Finally, Cockpit will prompt you to upgrade itself when you connect the tablet to the Internet. To check if your Elios 3 drone and Cockpit have correctly been updated, open the INFO tab in Cockpit and you should see the following update version (or later release) under aircraft and cockpit: 

1.2 Updated cockpit and E3

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Mounting the UT Payload on the Elios 3

Drone compatibility

The UT Payload is only compatible with the Elios 3. Elios 1 and Elios 2 drones cannot be equipped with this payload. Please make sure that no parts of the cage are broken before proceeding with the set-up of the payload.

Selecting the correct probe

When you purchase the full UT configuration, Flyability provides you with a choice of three different twin-crystal piezo-composite probes of varying frequencies: 2 MHz, 5 MHz, and 7.5 MHz.

  2. 2MHz probe 3. 5 MHz probe 4. 7.5MHz probe
Frequency 2MHz 5MHz 7.5MHz
Crystal size

12mm (0.5in)

9.5mm (0.37in)

4.5mm (0.18in)

Tip size

17mm (0.67in)

12.7mm (0.5in)

6.5mm (0.26in)

Use case

For attenuative material (e.g. coating) and thick surfaces

For general purpose and extremely heavy front/back wall pitting or corrosion

For small diameter pipes (e.g. boiler tubes, and thin corroded plates)

Given this information, please select the probe best suited for your next flight. For testing purposes, we suggest using the 5MHz probe.

Selecting the correct hood

Hood is the term used by Flyability to refer to the red cap placed around the probe together with the membrane to help improve the contact of the probe with the metal surface. Ensuring that the UT probe is in good contact with the surface being inspected is crucial for obtaining accurate and reliable results. For this reason, each probe is provided with two different hoods made for different surfaces.

  5. Hood for flat surfaces 6. Hood for pipes
Points of contact 3 2
Use case

Ideal for flat surfaces like metallic walls or ceilings

To use on all metallic pipes

Given this information, please select the probe hood that you will need for your next flight. For testing, we suggest using a flat surface hood.

Mounting the UT payload

Tools and items needed

Before starting to mount the UT Payload, make sure that you have the Elios 3 toolbox and the following items with you:

  1. 5MHz probe and flat surface hood
  2. Stiff gel pipe
  3. Axial rotation module
  4. LLM
  5. Long extension arm and clip
  6. Short extension arms and clips
  7. Side cutters
  8. Pliers
  9. T8 screwdriver (0.4Nm)
  10. Standard Elios 3 zip ties
  11. Cable clips for the cage
  12. Cable clips for the rotor arm
  13. Cable clips for the arm stiffener
  14. Grommet screws
  15. Gauge
  16. Tope cage adaptor
  17. Bottom cage adaptor
  18. Flexible gel pipe
  19. Luer syringe connector
  20. Quick release connector

Matteos work sheet

Watch this video to learn how to mount your UT Payload:

Please check that the cables and tubes are mounted outside the cage to avoid them falling into the propellers for any reason and make sure there is no dust before inserting the cable into the drone.

NOTE: Please make sure that you correctly placed the quick release connector on the gauge cable before inserting it in the Elios 3. See here how:


Once the UT Payload has been correctly plugged in and the systems have been updated, the drone will automatically detect the new Payload. If this doesn’t happen please try turning the drone off and then back on and waiting a few minutes. 

To make sure that the UT Payload has been detected you can check the payload configuration section at the top of Cockpit:

8. Cockpit payload configuration

Adding ultrasonic couplant

To add couplant to the Elios 3 UT Payload, follow these steps:

  • Choose the correct type of couplant. Flyability provides you with a 25cl bottle of water-based ultrasound transmission gel to get you started with your UT measurements.

Important! We do not guarantee the integrity of the equipment if you use non-water-based couplants. For instance, in previous tests, WD40 resulted in permanent damage to the equipment.

  • Mix the gel solution with water to obtain the desired viscosity (see the viscosity guide in the user manual). For your first test flight, you can use a 30/70 gel-to-water ratio.

Important! Water-based couplant may freeze under 5°C/41°F conditions and damage the payload.

  • Add the couplant to the smart syringe by using the syringe tool and install the syringe back into the payload. See how in the video below:

For safety concerns regarding the couplant provided to you by Flyability please refer to this safety sheet.


CAUTION! The smart syringe plunger may get blocked by repeated usage (normally >100x refills) or following a long storage period. We recommend before each flight to check if the syringe functions correctly and if this is not the case to lubricate the sealing of the syringe on all sides. When lubricating the pump, please also remove any dust particles you may find by using hot water and soap. Avoid using degreasing agents as a gel replacement.


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Available training

The drone is now fully set up and ready to fly but before you do so, we highly suggest that you follow a UT measurement training. When purchasing the UT payload, basic online training is included to take you through the different components of the UT payload and some basic knowledge on how to use it. It is possible to also purchase an OEM training option that will be done in person by the Flyability training team or one of its resellers. If you are interested in purchasing the OEM UT training please contact sales@flyability.com.

[Basic training module coming soon]


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Read the user manual Carefully read the Elios 3 UT Payload user manual and quick start guide before managing the equipment and performing a flight.
Laser warning Pay attention. The Elios 3 UT Payload is a class 2 laser product. For more information visit https://www.lasersafetyfacts.com/labels2.html 
ce-mark Flyability SA, EPFL Innovation Park BLDG C, 1015 Lausanne, Switzerland, declares under its sole responsibility that the product described in this user guide conforms with the EMC Directive 2014/30/EU, Low Voltage Directive 2014/35/EU and RoHS Directive 2011/65/EU.
      FCC This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.

This Class A digital apparatus complies with Canadian ICES‑003.

Cet appareil numérique de la classe A est conforme a la norme NMB‑003 du Canada.

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Getting ready for your first flight

Getting accustomed to the UT tabs in Cockpit

The first thing to do is select your desired unit of measure. To do so open settings on Cockpit and select the metric or imperial option:

9. Unit settings

Before conducting your first flight with the Elios 3 UT, we suggest that you get more accustomed to the updated Cockpit view and the specific UT tabs. To view the UT settings in Cockpit, turn on the drone and the tablet, wait for the UT Payload to be recognised, and then open Cockpit. Finally, click on the settings icon (⚙️) in Cockpit and click on UT. Below you will find an indication of what each tab can do:

10. Cockpit interface

11. Cockpit view 2

To get accustomed to the new UT tabs, we suggest performing some UT measurements when the drone is not flying.

For the first flights, we suggest that you leave the auto-gains and auto-gates turned on. For more information regarding single echo or echo-echo scans, please refer to the Cygnus Instruments website.


Turn on the system

Now that the UT Payload has been mounted, all the systems have been updated, you have read the user manual, and you have familiarized yourself with the new Cockpit interface, you are ready to perform your first test flight. To do so start by turning on the drone and the remote control.

Make sure that you are in a safe environment for flying the drone, that no one is close to the take-off point, and that you have the correct protective gear.

Routine before conducting a UT flight

1. Check that you have the correct probe and hood

Before starting an inspection, check you have mounted the correct probe and the correct hood for the task. See Chapter 8 on how to switch the probe or hood.


2. Make sure that the gauge is well-secured to the drone

For safety reasons, it’s important that you check before each flight that the gauge is safely secured to the drone structure:

12. Gauge locked


3. Perform probe gain compensation

When you first mount the UT Payload and every time you change the probe, it’s important to perform a probe gain compensation. This feature allows you to view with more ease the scans detected by the probe. To perform a probe gain compensation:

  • Turn on the drone and check that the UT Payload has been detected by Cockpit.
  • Have the calibration block, couplant, and the remote close by.
  • Place some couplant on the calibration block and place it against the probe. Then click on “Gain Compensation”.
  • When the gain compensation is complete you should receive a notification informing you about it. 
For more details on how to perform gain compensation check out this video:

[Video coming soon]


4. Perform probe zero

To perform a probe zero (also known as zero offset or zero calibration):

  • Make sure the drone is on and connected to the tablet.
  • Open the settings on Cockpit (⚙️) and select the UT tab.
  • Scroll the right-hand side of the screen until you find the option “Zero the probe”.
  • Then click on “Perform”.

Watch the video to see all the steps in action:


5. Perform calibration

It is important that you calibrate the UT payload every time you change the probe, you inspect a new material or there is a significant change in temperature. Perform a 1 point calibration when you are certain that the thickness of the asset is close to the thickness of the block. Perform a 2 point calibration when you want to measure different thicknesses in the same flight/inspection or when you don't know the thickness of the material you will measure. To perform a 1 point calibration do so:

  • Choose “1 point” in the interface and then set the toggle to “thickness”.
  • Select the calibration block corresponding to the material of the asset you are about to measure.
  • Power on the drone and tablet and set the initial parameters, including selecting the appropriate frequency for the first calibration block.
  • Place the first calibration block in contact with the UT probe. Choose a thickness as close as possible to the asset you want to inspect. Ensure good contact by applying couplant between the transducer and the calibration block.
  • Once the A-scan is clean and stable, press the “perform” button.
  • Confirm that the UT device displays the correct thickness of the calibration block. If there are discrepancies, try to perform the calibration again or perform a “2 points” calibration.
  • The date and time of your last calibration are displayed at the top of the calibration tab.

See here how to perform a calibration:

[Video coming soon]


6. Take your first measurement (not in flight)

By hand, move the drone and place the probe in contact with a metallic surface. Press the AUX button on the remote to dispense the couplant until you see it being dispensed on the probe. The payload should then automatically start measuring the metal’s thickness.

QUICK TIP! Always check before each flight that the smart syringe is attached to the UT module and correctly tightened.


7. Adjust the arm in the correct position

The UT Payload can be angled in different ways to allow you to measure almost any surface. You can position the probe to scan a surface above, in front, or below the drone. Watch this quick video to understand how you can change the angulation of the probe:

Here are some tips on how you can orient the Payload arm for better measurements:

Screenshot 2024-04-16 204143

IMPORTANT NOTE: Please pay attention when flying through narrow openings like manholes with the UT Payload mounted.

In vertical manholes, when the arm is oriented straight up (1), the Payload may touch the top of the opening and potentially unbalance the drone. The LLM will allow the arm to bend and assist you but in order for this to work you will need to maintain speed while passing through the manhole.

When the arm is oriented straight down (6) it is best to fly backwards into the opening. Flying forward through a manhole with the arm oriented straight down carries the risk of hooking the manhole with the probe, which will cause the drone to flip forward.

For horizontal manholes (e.g., 🕳️), the LLMs ability to bend the arm will allow you to fly through openings without any problem.


What does the color of my scan mean

You may notice that the thickness indication on Cockpit may change between red, orange, and white. This is because each has a different meaning:

13. Measurement colour code red No ultrasonic signal detected or too weak to be used.
14. Measurement colour code orange The signal is strong but changes a lot. The measurement is unstable.
13. Measurement colour code white The measurement is strong and stable (⚠️It does not mean its correct. This is up to the user to say ⚠️)

Testing the setup

Before performing your first mission with the Elios 3 UT, we suggest that you conduct a first test flight and UT measurement in a safe environment. This step is important to make sure that everything is working properly and that you can recover the drone safely in case of any failures. It is recommended that you pick an open room area where you cannot lose the drone.


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Your first flight


You are now ready for your first Elios 3 UT flight. Turn on the drone and the remote control, wait for the UT Payload to be detected, and take-off.

To perform a UT measurement while in flight, get close to the surface you want to inspect, wait for the UT payload to magnetically lock onto the surface, and dispense couplant by pressing the AUX button on the remote control. 2 or 3 seconds or until the A-scan appears on the screen should be enough. Elios will automatically scan the surface and save your A-Scan. If you are happy with the measurement, detach and move on to the next spot that needs inspecting. To make it easier to identify the measured spots in post-processing we suggest taking points of interest (POIs) every time you are taking a measurement.


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Problems you may encounter during a UT flight

Surface conditions

Contaminants on the surface, such as dirt, grease, or corrosion, can interfere with the coupling between the transducer and the material. Proper cleaning is necessary to ensure reliable UT measurements. When purchasing the full package, Elios 3 UT is provided with a dedicated cleaning tool that can be mounted on the drone. See here how to use the Elios 3 cleaning tool.

Out of couplant

If you run out of couplant during a flight you must return the drone to the take-off point and refill the couplant dispenser before proceeding with the next measurement. You will always be able to see the couplant level in the top left corner of the Cockpit:

16. Gel level

Surface curvature

The surface curvature may influence the contact between the transducer and the surface, leading to possible noise in the scans. To limit this issue, Flyability provided you with a hood designed specifically for pipes. For small pipes, we also suggest using the 7.5MHz probe. 

See here how you can switch hoods:


Surface smoothness

When the surface is very uneven due, for example, to heavy pitting, the sound may not bounce back correctly and it could be difficult to receive a correct measurement (most likely orange reading). In this case, try detaching from the surface and reattaching to a different spot but close to the original one.


Bad coupling

Sometimes, despite the patented lip, when the surface is a bit dirty or uneven there could be some air trapped between the probe and the surface. It can be difficult to understand when this is the case so when you have a bad reading (red) of the surface we suggest always trying to detach and reattach on the same spot of couplant or simply trying dispensing more couplant to see if the issue is caused by an air bubble.


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How to use the Elios 3 UT cleaning module

When the surface conditions start to become difficult to measure (e.g., heavy dust or light rust), the first thing you can do is switch to the 2MHz probe. If this is not enough to get a clear A-scan, you may want to consider using the cleaning module provided with all premium UT packages. This tool is ideal for removing thin layers of dust and dirt from the surface you want to inspect. To use the cleaning module:
  1. Remove the UT probe and gel pipes. Then mount the cleaning module as shown in the video below and connect the cable to the gauge.
  2. Once the cleaning module has been correctly mounted, fly to the spot you want to measure and place the cleaning tool over it. You can help yourself to pick the correct spot by using the laser. The magnets on the extremities of the tool should attach it firmly to the metal surface.
  3. Once attached, create a POI of the spot you are cleaning so that you will be able to easily find it again later in the 3D map.
  4. Press and keep pressing the AUX button for around 20 to 30 seconds to perform the cleaning process.
  5. Detach from the surface and you should now see a round cleaner spot. If no other spots need cleaning, exit the asset and remove the cleaning tool.
  6. To continue with the UT inspection, mount the UT probe and gel tubes back on the drone and using the live map locate the POI recorded. Fly to the POI and with the help of the laser measure the surface that has been cleaned.


[video coming soon]


Please remember to close the gel tube with the provided cap every time the cleaning module is used. This helps avoid any unwanted particles entering the gel dispensing system.

Please consider that using the cleaning module can have an impact on the drone motor's maintenance time and on the front payload camera sanity as unexpected metallic dust and particles can be torn off from the surfaces. 


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Maintenance and care

Please find all the general maintenance information about the Elios 3 here. For any additional concerns regarding the maintenance and care of the UT Payload please read the following chapter or contact our support team at support@flyability.com.

Handling the UT Payload

Properly cleaning and storing the Payload will reduce the risks of damage. Be aware that strong collisions may also be harmful to the Payload and therefore it is not suggested to store it at height or where it may fall.

Do not remove the Payload in particularly dusty and dirty environments to avoid particles entering the cable and connector which could damage the Payload. 

Removing the UT Payload

If you wish to remove the UT Payload to conduct visual or LiDAR inspections you can watch the video here below to learn more:


We suggest that you remove the UT Payload every time you conduct an inspection that does not require collecting UT measurements as there is an increased chance of crashing the drone when the UT Payload is mounted.

Storing the UT

When storing the Elios 3 UT Payload we suggest placing it back into the original box that it arrived in and away from direct sunlight. Although no damage should occur, we suggest storing the Payload in a dry and dark environment at room temperature. Please pay attention that no dust or dirt enters the gauge and gel dispensing cables.


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Support and contact information

For all support information please access the Flyability Knowledge Base at the following address: https://knowledge.flyability.com/ut-payload or contact us at support@flyability.com.


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Technical specifications

Please find and download the Elios 3 UT technical specifications here.

UT Payload method statement

Please find and download the Elios 3 UT method statement here.


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