Key Risks in UAV Operation

Below is a list of key risks which has been compiled over many years of piloting of which a large proportion have been in and around Miami, Florida. Some of these may be obvious but others less.

• Failure of a motor – if no redundancy is available, then this will lead to a crash with a high chance of hitting either a person, vehicle or property not under the control of the pilot
• Power failure – losing power to the UAV will generally result in the aircraft falling vertically towards the ground with potentially devastating consequences
• Failure of autopilot – there are many things which can fail on an autopilot and this can lead to unstable behaviour and a crash
• Loss of line of sight – it is very easy to lose the UAV over the horizon when operating in built up areas. Generally you are surrounded by buildings, and if the pilot is not concentrating it can be easy for the UAV to be lost behind a rooftop resulting in a collision
• Loss of GPS – losing GPS is never a good thing and will result in the pilot having to take over manually to rectify the situation. If the pilot is not trained well or not concentrating this can result in a crash. Flying in and around tall buildings increases the chance of either losing GPS, or even worse getting GPS reflections which can cause unstable behaviour
• RF interference – cities are full of Wifi signals and so it is far more common to experience loss of links. A loss of link should result in the aircraft returning to home, however this can be problematic especially when facing GPS issues. If a tall building is between the UAV and the home point, this return to home sequence can result in a collision
• Magnetic interference – metal in the ground as well as sources of high voltage DC power can cause unstable flight characteristics. Due to these sources being near the ground, they present a risk during take-off and landing of a collision with a nearby object or person
• Wind turbulence – when operating close to tall buildings and in high winds, UAVs can be subject to pretty fierce wind turbulence from air being forced around buildings. Especially with tall buildings in Miami this can cause the aircraft to momentarily become uncontrollable resulting in a crash
• Birds – a whole range of different birds live in our cities, some of which like to flock in large numbers and some of which are rather territorial. The risk of a collision with a bird is something which many people do not consider, but is actually quite significant
• Collision with buildings – operating in congested areas with tall building is difficult at the best of time. A momentary lack of concentration can cause a pilot to misjudge distances between the UAV and buildings and result in a collision
• Collision with aircraft – operating in cities such as Miami Beach, there is a huge amount more air traffic compared to other places. Low flying helicopters are fairly common, and if flying at high altitudes the risk of a collision is much greater than in more rural settings
• Distraction of drivers – when operating close to busy roads, it is easy for drivers to become distracted especially if they see a UAV hovering by the side of the road

There are many other risks that could be included here, but this covers the most common ones. The next thing to consider is how we can mitigate these risks…