Transmission towers

Close visual

Close visual inspection of transmission towers for Nampower as part of the Maintenance Project.
Client: Nampower
Location: Windhoek, Namibia
Date: November 2014

The Mission

Our RPAS allowed us to inspect transmission towers for defects while the towers stayed live, thus removing any safety issues or the need to ask for outages.

Unmannedtech's solution and results

We identified numerous defects in the course of the inspections. This enabled SSE to make decisions about the priority and schedule for investigation, maintenance and repairs, thus minimising any disruption to the transmission line network.


Powerline inspections

powerlines powerlines

Construction site

construction site construction site

Read the case study below for a roof inspection done by Unmannedtech in the Commercial Inspection & Data Management industry.

Case study

Industry: Commercial Inspection & Data Management
Region: Toronto, Canada


Roof Inspection: The traditional method of performing a roof inspection employs hand-held thermal imaging equipment or, when required, equipment mounted on manned aircraft. Irrespective of the method of data acquisition, the basic science of failure and detection can be described as follows:

  • The substrate insulation on an industrial roof can be prone to degrade, which allows moisture to penetrate the roof in certain areas
  • Areas with substantial moisture penetration lose the ability to insulate (the “R-value” essentially becomes zero) and causes energy (heat) to dissipate into the environment
  • During the day, the roof is heated by the sun (Solar Loading)
  • At night, the areas with dry insulation cool more quickly than the areas with wet insulation. The result is a visibly different thermal signature in the infrared (IR) spectrum, which enables inspectors to identify areas in need of repair
  • A regular, accurate maintenance program minimizes heating and repair costs of the structure

Façade Inspection: Buildings consume energy – it is estimated that as much as 30% of all energy produced goes to commercial, industrial, or multi-unit residential buildings. Of this 30%, as much as 40% can be lost immediately, and 90% of this loss occurs within only 1% of the envelope. Put differently: a tiny fraction of the exterior of the building, generally at connection points between roofs and walls, is responsible for the vast majority of energy loss, and identifying/addressing these areas is critical.

The broader economic and environmental issues stemming from building energy loss are significant, and range from the carbon footprint from generation of “wasted” energy, to the impact on landfills of unsalvageable building materials which need to be replaced in the event of damage. Accordingly, governments have introduced legislation mandating periodic inspection.

Because the areas of energy lost tend to be small and hard-to-reach, RPAS become the more economical and safe means of acquiring the necessary data. Moreover, the resolution of the data is critical: chipped bricks captured in a narrow field-of-view EO (visible light) image may be indicative of water ingress, and the precise overlay of a thermal image can help an inspector assess cause-and-effect. As with roof inspection, RPAS can capture thermal imagery at 90 degrees to the façade, vs the oblique angles of handheld detectors on fixed-position lifts or harnesses. Thus, RPAS technology ensures the highest accuracy thermal readings possible.


The building envelope inspection industry encompasses data capture of both roofs and façades (exterior walls). Both operations involve thermographic and electro-optical (daylight) imagery, with the thermography generally undertaken at night to ensure accurate data.

As well, reducing the time and resources needed for the inspections is a priority. For example, a roof with an area of 1 million square feet (equivalent to roughly 4 big-box hardware stores) takes a standard 2-person crew performing a night-time inspection 5-7 days under optimal conditions. Precipitation/inclement weather may force the project to be rescheduled to ensure consistent data collection across the roof.

When Unmannedtech started the process of evaluating RPAS, they focused on both a high standard of operating capabilities, as well as the broadest set of safety provisions within the RPAS. Equally important was the operating stature of the provider of the RPAS, particularly in an industry characterized by a lot of unproven technology from early stage companies.



Aeryon presented a proven track record across demanding applications in industrial, as well as military and public safety sectors, and had the corporate wherewithal to deliver high levels of customer service, custom developments, warranty commitments, etc. – all the ancillary aspects that turn a product into a solution.

The SkyRanger itself proved to be class leading in payload performance, wind tolerance, and presented an optimal blend of small size and robust performance.

Aeryon was also able to meet Unmannedtechs specific requirements with the development of a customized IR payload optimized for thermal-mapping applications.


RPAS technology presents clear and repeatable ROI for the building maintenance industry. Using Aeryon SkyRanger sUAS:

  • A roof inspection can be completed in as little as 1.5 hours
  • Data capture is more accurate, enabling prompt response and repairs
  • Risk is minimized due to the absence of personnel on the roof
  • Inspection time is reduced by 95%
  • Lower cost inspections can occur more frequently
  • Energy/heat loss, corrosion, mold, and other symptoms of “sick building syndrome” are identified sooner


  • Reduce the need for inspectors to walk the roof in the dark
  • Eliminate risk of injury, the numerous trip-hazards (HVAC equipment, uneven surfaces, etc.)
  • Decrease time to inspect a roof
  • Lower cost of employing a team of inspectors
  • More accurate image capture – a camera pointing straight down is more accurate than images captured at an oblique angle (i.e. handheld IR imagers).

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