Unmanned aerial vehicles

Permission for take-off

Unmanned aerial vehicles can substitute for humans in some high-hazard activities but the authorities exert tight controls to ensure their safe use. 

Image credit: Cyberhawk

News footage that followed the Grenfell Tower fire in west London in June featured London Fire Brigade remotely operating a small rotor-borne aircraft to survey the building’s damage and to search the upper floors for survivors.

These unmanned aerial vehicles (UAVs) are increasingly used by emergency services to inspect structures that are too risky for rescue teams to enter. Commonly known as drones (though, strictly speaking, a drone guides itself), they can be equipped with high-definition cameras to capture live pictures and thermal imaging technology to detect body heat.

In the construction, oil and gas, renewables and utilities sectors more organisations are using UAVs as an innovative inspection tool in high risk environments, removing the need for operational staff to carry out risky work at height or in confined spaces.

Remote access

London’s water utility, Thames Water, which has thousands of large cranes, chemical tanks and water towers that require internal and external inspections, has planned more than 100 days’ work this year using UAVs for close-up inspections. The craft speeds processes, eliminates safety risk and is expected to produce £1m savings this year.

If you think of [our] chemical tanks, large digesters and pressure vessels, we would always shut down those installations and then go in and erect scaffolding inside and outside,” says Karl Simons, head of health, safety, security and wellbeing.

“Every inspector knows the points that he wants to look at on any large vessel or tank. Many of these are marked up, and [using the UAV] we can see if there have been any issues such as erosion or movement. The UAV provides a close-up visual of what the inspector would normally look at if he was up on the scaffolding.”

Thames-Water-unmanned-aerial-vehicleSimons adds that an important element of this substitution was working closely with the firm’s insurers and regulatory inspectors, who are responsible for signing off the vessels and tanks as fit for purpose: “We have to ensure that all parties are totally comfortable with the way this process is being carried out, otherwise it wouldn’t happen.”

As an early adopter, Thames Water has developed an essential standard, a contractual obligation across its entire supply chain, which outlines the essentials for operating a UAV (see graphic on p 36). None of its contractors can fly a craft without first securing an Operational Safety Authorisation, approved by the security team.

UAVs are well established in the UK’s wind sector for operational and maintenance inspections. Both the safety risks and the significant cost associated with sending skilled technicians to offshore turbines – the need for hazardous transfer from a boat to the transition piece (the shaft that holds the turbine aloft) and work at height to survey the tower, nacelle or blades – are reduced dramatically by using UAVs, says Chris Streatfeild, director of independent risk management consultancy Forge Risk and former director of health and safety at the industry body RenewableUK.

“When you used to do blade inspections, you either stood at the bottom of a turbine with a set of binoculars or you had to physically send someone up using rope access techniques or deploy expensive man-riding lifting aids,” he says.

“Not only do they have to be safe in being able to access that turbine, but they have to be technically competent to carry out the inspection.”

To get your permissions you need to have quite a robust operations manual. It goes through everything in fine  detail and the CAA can refuse

This is often no longer necessary, he adds. “An expert would be able to sit remotely with a high-resolution camera doing the inspections and could do many more inspections. All he needs to do is tell the UAV pilot where to position the camera. It’s a much more efficient process. When combined with ever-more advanced software and global positioning system (GPS) capability, UAVs will play an increasing role in reducing risks and improving the operational efficiencies across the wind sector.”

Future applications could offer even greater safety gains. Much in the same way that surgeons can use robots for remote surgery, Simons believes that more sophisticated UAV models will one day be able to undertake more challenging work at height operations, such as welding, directed by operatives safe on the ground.

“That’s where I see it in the future,” he says. “I’ve always been a big fan of removing the human ability to fail ... What’s to say that operational maintenance can’t be undertaken by someone sat in a cabinet and who sends the UAV out to the area to do the inspection and maintenance and then flies it back?”

Video: Thames Water UAV capabilities and asset inspection

Video supplied by Thames Water


Pilot competence

In the UK, the Civil Aviation Authority (CAA) polices the regulations on UAV use under the Air Navigation Order 2016 (ANO 2016), and it also issues the permits to fly (see "UAV fact file box" below).

The CAA’s list of approved commercial small unmanned aircraft operators (bit.ly/2v8ujcw) provides a snapshot of the range of UAV users.

This includes the construction industry, in which the technology can be used, for example, for initial site investigations and to produce topographic surveys.

Dean Overton, partner at Overdrones, which carries out surveying and modelling in the sector, says that at the building stage, UAVs can also be programmed to fly over and around a building regularly, following the same path. The data captured can then be compared with building information modelling (BIM) information to see if the project is on time.

In oil and gas, UAVs mounted with thermal imaging cameras are flown along pipework to identify leaks. In the waste industry, a similar approach is taken to methane detection in anaerobic digestion.

Despite these innovations, take-up has been slower than expected since the CAA produced its first guidance for small UAVs in 2002, although there has been a surge of interest in recent years.

Angus Benson-Blair, chief UAV pilot at aerial film and television production company Flying Pictures, qualified as a UAV pilot in 2013 and was the 171st pilot to be certified. More than 4,000 have gained certification since, a figure driven by a fall in set-up costs. Many have subsequently dropped out or joined forces and the CAA registers just over 3,000 current “active” operators.

Benson-Blair told IOSH’s Sports Grounds and Events Group at Twickenham Stadium in May that top-of-the-range equipment, which would have cost about £65,000 in 2013 can now be bought for as little as £10,000. At the other end of the scale, the Phantom 4 – the go-to aircraft for basic UAV flying – can be purchased for £1,500.

UAV fact file

The UK Civil Aviation Authority (CAA) website outlines the requirements for flying an unmanned aerial vehicle (UAV) commercially (bit.ly/2urpRVc). These include the regulations relating to UAV use, permissions and exemptions and general guidance.
The Air Navigation Order 2016 sets out the regulations that govern UAVs. Crucially, the pilot must maintain direct, unaided visual contact (known as line of sight) with the UAV to ensure that it does not collide with other aircraft, property or people.
The UAV must be kept within 500 m of the pilot, who is permitted to wear corrective spectacles but cannot use binoculars, telescopes or any other image-enhancing devices to track its movement. UAVs can, in some circumstances, be flown beyond the line of sight but the CAA requires the pilot to show that they can activate another method of collision avoidance. Further information covering this can be found in the CAA guidance (bit.ly/2fertPp).
UAVs must be kept below 120 m to reduce the likelihood of conflict with manned aircraft.
All commerical and private operators must comply with both the Civil Aviation Act and the Health and Safety at Work Act.
Anyone interested in training to become a UAV operator should first contact one of the National Qualified Entities that run the assessment courses on the CAA’s behalf (bit.ly/2txMI5d).
The price for permission depends on the UAV’s weight; current charges range from £173 to £1,211, but there is no limit on the number of UAVs. The pilot will also have to obtain insurance that meets Regulation (EC) 785/2004 requirements.

“Your course to get qualified [as a pilot] by the CAA is another £1,400, so for £3,000 you can now enter the film industry or any other industry you want to service,” he said.

Safe to fly

Even so, anyone planning to operate commercially – defined by the CAA as someone undertaking flights for business purposes for remuneration – or flying privately for business purposes, must first obtain a permission from the CAA.

“Commercial operators” covers a variety of flight applications, most of which involve aerial photography. A commercial operator would, for OSH purposes, include a third party contracted by a site owner, say a construction firm, to survey a site.

To do this, all commercial UAV operators are required to obtain a Permission for Commercial Operation. This can be secured only after the pilot has successfully completed a course run by one of the National Qualified Entities, which are CAA-approved bodies that assess the competence of people flying small UAVs. The course is designed to test the applicant’s understanding of aviation theory. It also requires them to write their own operations manual and pass a practical flight assessment to prove remote pilot competence.

“All they want to see from the pilot is whether they can get the aircraft up,” says Benson-Blair. “Can you fly it in a controlled manner, around in a circle, maybe a couple of figure of eights but not a lot more than that? You are using some pretty good aids, like GPS.”


Stuart Thomas, survey manager at Cyberhawk, a Scottish-based UAV operator that undertakes work for oil and gas clients, says the operations manual is the most important part of the permission’s application. Not only does it set out the standard operating procedures for the type of flights proposed and how to deal with emergencies, it also covers who will be operating the UAV, extra equipment such as cameras, and how the operator will ensure the vehicle remains airworthy.

“To get your permissions you need to have quite a robust operations manual,” Thomas says. “It goes through everything in fine detail and the CAA can refuse [to give you a permission] if they don’t deem that your procedures are up to scratch.”

Lost now

The standard permission is the most common but UAV operators who require approvals with greater privileges – when higher-risk work is involved – have to submit an operating safety case to the CAA. Permissions or exemptions are valid for up to 12 months and the CAA renews them yearly. Operators must also buy third-party insurance.

For most OSH applications, the standard permission should suffice. The ANO 2016 (see fact file) sets out the restrictions on UAV use in a congested area – defined as one that is used mainly for residential, commercial, industrial or recreational purposes.

Cyberhawk-wind-turbine-UAV-inspection-dronesThe height and distance rule obliges all operators to maintain line of sight to the UAV to avoid collisions with other air users.

“The big point that the CAA always makes is, you’ve still got to be able to see it,” says Benson-Blair. “Not see it as a pinprick but be able to easily reacquire it.”

The ANO 2016 makes no distinction between indoor and outdoor flights. Although it states that “certain hazard factors are heavily mitigated by the fact that the aircraft is flying in an enclosed environment and access to the venue can be controlled”, UAVs are treated like any other occupational risk and covered by safety and health legislation.

Simons says: “As far as the Health and Safety Executive [HSE] is concerned, it’s a piece of equipment and if you are introducing it, they’d expect you to have a risk assessment to ensure its controlled use.”

The CAA and HSE operate a memorandum of understanding that outlines the enforcement lines between the two regulators (bit.ly/2sDxgzm). With the exception of military vehicles, this states that the CAA is responsible for safety and health once the UAV is powered up and until it is turned off after flight.

 Planning the flight

Source: An extract from Thames Water’s Essential Standard Number 28 – Working with Drones

Melvin Sandell, HSE inspector for the leisure and entertainment sector, says the CAA has accepted jurisdiction, even if the UAVs are flown indoors.

Benson-Blair, however, argues this is a “grey area”. He believes that, due to the lack of threat to other air users, the CAA is unlikely to show any interest in any indoor incidents and the HSE may have to take the lead. He identifies two potential safety issues relating to indoor use. The first involves flying UAVs in public buildings while cleaners are working in the evening or during night shifts. The second relates to the small risk of fires.

“If a UAV crashes ... you could end up with people getting hurt or killed due to the resulting fire rather than the crash itself,” he says. “We fly with lithium polymer batteries and while I carry a fire extinguisher with me, it is not to put the battery out because it won’t. You use it to put the resultant fires out.”

Although the use of UAVs indoors is less common, Overton says this is where there is a growing demand. 

“[There is the] decommissioning of nuclear facilities but also the oil and gas offshore industries and mining. These will mean UAVs flying in restricted areas and in hazardous environments. The HSE’s role will become much more prominent.”

Site procedures

Thomas at Cyberhawk points out that UAV operators contracted to carry out work for clients will have to prepare risk assessments and method statements up front. An assessment includes UAV-specific hazards, such as piloting skills and the vehicle’s return-to-home function should the pilot lose control.

Dynamic risk assessments can also be carried out by contractors on arrival at the site. “If there are, for instance, more plant movements than usual, we can stay behind a fence, erect a barrier or use beacons on our vehicle. There is an opportunity to ‘beef up’ your safety in light of something that you may not have thought about before you got there.”

Safety procedures must also include a take-off and landing spot that is physically separated from the workforce and a back-up in case the primary location cannot be used.

Site inductions should brief pilots on safety issues they need to be aware of, such as the storage of flammable materials or any potential helicopter landings that would require evasive action. For both contractors and in-house operators, site supervisors and operatives need to be alerted to the UAV’s use as part of briefings.

“It’s the same as when there is heavy machinery coming on site,” says Simons. “The message is that it’s treated in the same context as any other risks on site.”

Due diligence

Benson-Blair cautions OSH professionals about rushing to hire anyone before first undertaking the necessary checks.

“When you start choosing your operators, bear in mind that there are an awful lot [of people] out there who will promise you the world and won’t necessarily deliver because they themselves are at the beginning of the curve,” he says.

His advice on due diligence is to ask the operator what they would do if the UAV fails, what their maintenance schedules are and how maintenance is logged. “Sometimes the operator may be wary about giving you that information because some is valuable intellectual property. [But] … you’ll very quickly get an idea of whether they are on top of how they look after their equipment.”

There are two pieces of paperwork that clients should always check: the operator’s insurance and the permissions document. Benson-Blair says a legal operator will hold a valid Permission for Commercial Operation and should provide that on request.

Overton adds: “As long as you have checked that the pilot has his Permission for Commercial Operation, and you’ve seen their competency certificate for flying and insurance, they have done everything they can possibly do.”

As a rule of thumb, Overton always recommends two pilots: one to fly the UAV and the other to operate the camera. He also insists on machines with at least six rotors. “If it’s anything less than that and a rotor fails, and the UAV comes down, you cannot control it. It’s going to land and land fast. A UAV with six rotors has in-built redundancies, so if it loses a rotor you can still fly it.”

Benson-Blair believes that an adoption of a just culture among pilots is vital to raise standards.

“Unfortunately, it’s an ethos that we are finding really hard to get among the industry,” he admits. “We have a lot of people who come from backgrounds where the idea of admitting to a mistake is a complete anathema … This is a mindset that we are trying to change but it’s an uphill battle.”


Nic Warburton is acting editor, IOSH Magazine

 Nick Warburton was previously acting editor of IOSH Magazine. Before that he was editor of SHP and he has also worked on Local Authority Waste and Recycling and Environmental Health Practitioner


  • A very interesting article, i

    Permalink Submitted by Jason Kennedy on 7 August 2017 - 08:14 am

    A very interesting article, i know that UAV's are used in demolition to film the blow downs and inspect buildings afterwards.
    I believe energy companies could use these to inspect the power lines in certain circumstances, as currently they use helicopters to perform this task, surely this would be more environmentally viable and save some money, you never know it may help to bring our bills down.
    Obviously there would be some restrictions of use flying near power lines but surely no more than flying a helicopter.


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