Managing Mast Inspection with Drones: An AT&T Case Study

by coptrz on June 13, 2017

Mast Inspection Using Aerialtronics DroneCommercial organisations across the globe are waking up to the power of drone technology for surveying, including the major benefits offered for mast inspections – as shown by AT&T in the United States. Before we take a look at the case study, let’s delve into just a few of the many reasons that businesses around the world are using drones for inspections on cell towers, radio masts and other traditionally difficult-to-manage structures.

Safety First

Masts for radio and mobile signals are by their very nature very tall structures. They can range from 40 feet right up to 2,000 feet – that’s a long way to climb.

physical mast inspection

Unmanned aerial vehicles (UAVs) are improving the safety of all maintenance, repair, and survey works for masts. An engineer keeps his feet safely on the ground and uses video and photo feedback from a drone to make sure he knows what he’s getting into.

A drone can identify small problems, but it can also demonstrate a structure that is not safe to climb – something previously unknown by engineers until they are already on it.

Sending a drone up prior to a technician’s climb makes for a much swifter analysis of the situation and faster repairs. A drone can send back vital information about the location and type of issue detected, so an engineer can go directly to the right spot without spending potential hours locating it – and take only the tools required. He won’t have to either take every possible tool with him on the first climb, or return to collect the one thing needed but not taken!

Cost Efficiencies Gained from a Drone Inspection

The time saved by deploying a drone for a mast inspection is significant. Whereas previously an engineer would be required to harness up, climb, and inspect every inch visible for potential issues, a drone can do this in a matter of minutes.

Using a drone for an initial inspection means that an engineer also only needs to make one direct trip to the issue in question: once identified by the drone, the right equipment, tools, and replacement parts can be selected while on the ground. This can significantly reduce the time taken for each mast, enabling several inspections to be completed by the same engineers in one day.

Reduce Ecological Impact with Drones

nesting birds during mast inspection

Birds are a common problem when it comes to mast structures: the towers make for excellent resting areas. This causes several difficulties to any company that needs to maintain, repair, and update technology on a mast. In many countries, such as the United States, construction work can’t be carried out if birds are currently settled or nesting on a mast.

In the past, this would have to be confirmed by certified ornithologists who would sit and watch each mast at a time, for a number of days, to identify bird behaviour and determine whether nesting was taking place.

Now, as implemented by AT&T as an example, drones can be sent up to check the mast for nests in a matter of minutes. The drone is guided to fly in a non-offensive pattern and can be flown relatively far away from the mast to avoid causing disturbance to any birds in the area. This tactic works in two ways: it doesn’t cause unnecessary distress to nesting birds, and also prevents the drone becoming a target for larger predatory birds who have been known to take UAVs down mid-flight.

AT&T: The Mast Drone Inspection Case Study

multiple mast inspections

AT&T, the largest telecommunications company in the world, has implemented drones for inspections across their 65,000 mobile (or ‘cell’) phone towers across the United States and seen a remarkable shift in efficiency as a result.

With so many tens of thousands of towers, across such a broad geographical location, maintenance is required on a daily basis. On any one day, up to 15,000 engineers will be deployed to repairs or upgrades on masts.

Beneficial Changes in FAA UAV Regulations

A well-timed change in the FAA regulations regarding drone flight restrictions has enabled AT&T to extend the trial program to a business-wide roll out. This change retracted the earlier 500ft rule: a UAV could not be flown within 500ft of a non-participating person. Of course, in urban areas, such a ruling creates a problem for drone mast inspection. Now that has been revised, the UAV must only not be flown directly above a non-participant, allowing drones to be used in urban and more populated areas with ease.

How AT&T Use Drones for Mast Inspections

AT&T use drones to feed back photo and video feeds to the engineer on the ground, where the accurate visual representation enables a clear and quick plan of action to be made. Rather than a day per mast, tasks are now taking hours, thanks to the time savings offered by sending a drone up first.

Sometimes other technology can be used where required, such as photogrammetry and LIDAR, although this is on a case-by-case basis and may be applied in individual situations, such as creating 3D terrain models to anticipate the installation of a mast, rather than for a general mast inspection.

The telecommunications company is now experimenting with altered artificial intelligence (AI) programmes to improve the efficiency of drones in mast inspection to enable the UAV to make decisions before sending feedback to the ground. For example, using face recognition technology based around normal components of a mast, an AI application can decide when it has seen a fault and feed just that information back – making even the drone search much quicker than it is already.

The company is determined to communicate that the use of drones, even with the new AI experiments, is to augment the work of an engineer and enable them to carry out work more safely: it’s not a case of replacing engineers with drones. It does, however, report a 900% savings benefit since the full rollout of the drone program in 2016.

Using Low Flying Drones: The Stadium Study

AT&T also has masts in stadiums and large arenas. The low-flying ability of drones means huge areas can be covered in a minimal amount of time. Network coverage can easily be checked in hours without AT&T staff sitting in each individual stadium seat and testing upload, download, and latency speeds, which took a week at best.

cell tower mast inspection

AT&T isn’t just using UAVs for mast inspection, the company has also found that they can use drones to discover where interference is occurring in their network coverage: a drone can detect interference more accurately and help pinpoint nearby structures or other potential contributing factors to interference. Once again, this is done swiftly and thanks to the higher position of a drone than a person in a stadium, will often pick up interference that may have been missed by a person on the ground.

Drones Level the Playing Field for Small Operators

One of the great things about drone surveying is that small contractors in local areas can bid against larger companies for the same mast inspection contracts, with a great proportion of success. There are several reasons for this:

– A local contractor is likely to know the area, the weather, and the unique nuances of the region unlike a large contractor from out of the area

– A local drone company won’t need to charge for travel expenses across the country or even the globe, significantly reducing overall operational costs

– Many large companies, including AT&T, are not considering internal drone departments because of the time it will take to find and cultivate the right expert level of skills. Local companies already have this advantage!

The Future of Mast Inspection Using Drones

The case study of AT&T demonstrates the broadening commercial possibilities for drone pilots and drone companies across the world. More and more companies are beginning to recognise the safety and cost benefits to using drones as a support tool for their existing workforce.

Coptrz runs a Mast Inspection Course for drone training – a great opportunity for UAV pilots to make the most of this new and expanding niche. Speak to one of our experts or take a look at our range of professional courses.