Drones are becoming increasingly commonplace in urban areas for a range of commercial tasks. This can be everything from building inspections to filming for TV or adverts. What is often misunderstood, however, is the complexity of flying drones in these areas. London can be a challenging city to fly in due to its major airports and high-density buildings amongst many other factors. In this article, we will give you a sneak peek into the complex world of drone flying in urban areas and why it is important to hire an expert drone team for your next project.
Considerations When Flying In Dense Urban Areas
Flying drones in cities like London can be complex operations and there are a lot of factors that need to be considered before taking off. Following are some of the considerations we must undertake and plan before we arrive on site to start flying a mission.
- Site Access and Trespass – this might not seem the obvious place to start planning for flying drones, but we always check that we have permission to be on the site. This could be from the landowner, the local authority, private residents, commercial premises managers. If we don’t have permission, we can’t take off or land in their area. This gets more complex when considerations when ‘not visible’ ownership exists for example National Trust or Woodland Trust land, by-laws by regional or local authorities – the list goes on!
- People – With such a high population density, there are always people around who could be put at risk by our drone operations. We undertake thorough risk assessments to make sure that everyone is safe during our flights. Wherever possible we provide pre-notifications, always have a ground crew supporting the pilot and ensure warning signs are highly visible to the public/people not involved in the drone flight. In some cases, we will gain permissions from the Local Authority to close off roads or footpaths to maximise people safety.
- Airspace – London, where we are based, has some of the busiest airspace in the world with five major airports and a lot of other flying activity taking place. It is important to make sure that we are not going to conflict with any other aircraft.
There are also a lot of restrictions on where one can fly in London, so it is critical that we do our research before we take off. Aside from the CTR (Control Zones that surround airports) London has additional areas to consider – R157/8/9 are heavily restricted areas and require express permission from the Metropolitan Police Diplomatic Services which can take up to 2 weeks to obtain – without permission the drone will literally ‘not take off’ as the signal is blocked by an invisible ‘security dome’. In addition, London Heliport is a heavily controlled area and we ensure that we gain and respect all the permissions required to fly there.
- Visual Line of Sight – it is a requirement of our Licence to ensure that (amongst many other factors) we always maintain eye contact with the drone. In dense urban areas this can be a significant challenge as buildings and other structures, as well as trees can potentially obscure the pilots’ line of sight.
- Buildings and Structures – Another thing we must consider is the buildings. London has a lot of high-rise buildings, and it is important to make sure that we are not going to damage any property. Less visible are other factors of high-density buildings, for example ‘wind sheering’ whereby the wind is affected by the buildings and can cause very extreme effects on the drones’ flight performance.
- Drone Signal Interference – Drones collect information from satellites whilst flying to help maintain their position. Structures that are dense in metallic materials, Wi-Fi signals from offices and housing, as well as other sources of electro-magnetic interference (EMF) can be highly perilous to urban drone operations. Checks are made in advance and on site to test for EMF to minimise risks.
- Weather – Most drones available to fly in restricted urban areas are surprisingly small (often under 250g) to minimise safety risk and to comply with regulatory requirements. This limits the weather in which they can be flown with both wind and rain being of key concern – high winds risk the drone being blown off course and rain does not mix well with drones (as with all water and electrics). Extreme heat or cold result in other risk factors becoming apparent.
A 'Simple Drone Roof Inspection' - Not As Simple As It First Appeared
On behalf of commercial or residential customers we are often requested to carry out roof condition inspections. This request was in Kensington, London and it was for a 3-storey high managed residential building with no available roof access. On paper this is normally a straightforward requirement once initial pre-flight planning has been undertaken and can be carried out normally within a few days or a week.
However…
As we worked through our standard pre-flight planning process, looking at the factors mentioned above, the complexities started to increase:
- Restricted flight area (R157) Hyde Park: requiring us to submit a full flight plan, to gain permission from Metropolitan Diplomatic Services and Battersea Air Traffic Controller, notification to the Met Police and to acquire ‘drone unlocking codes (so that the drone could take off).
- London Heliport Zone: this restricted area also overlapped the site area and required us to gain permissions from their Air Traffic Controllers.
- Proximity to Railway Line: the building was less than 50 metres from a busy mainline railway line so permissions and safety measures had to be factored in to gain approval from Network Rail.
- Storm Eunice: had arrived on the shores of the UK and for weeks fluctuated weather forecasts and the weather itself with high winds and rain.
- Visual Line of Sight: this building wasn’t particularly tall but due to narrow streets and other tall buildings surrounding it the pilot had to compensate to ensure the drone could be seen at all times.
The outcome
Whilst not the most complex task we have undertaken, it took two weeks to plan and gain approvals for the drone inspection, another five weeks to align this with suitable weather. The inspection was successfully carried out and cost (time and money savings) twenty times less than any other option the customer could have considered.
Why You Should Hire An Expert Drone Team
While flying drones in London can be complex, we have a lot of experience in doing so. Our team have been certified by the Civil Aviation Authority and who have extensive experience of flying drones in London and other areas around the UK. Our team plan the whole operation and secure relevant permissions to make sure that everything goes smoothly.
