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Yesterday the CAA (Civil Aviation Authority) released a risk assessment document specifically targeting the use of UAVs near manned aircraft. CAP 1627 – Drone Safety Risk: An assessment. This document is no formality! In 2016, 70 incidents of UAVs and commercial aeroplanes having near-misses happened at Heathrow Airport. Also in October 2017, a UAV came within a few feet of an Airbus A321 as it was landing in Heathrow. It was reported that it passed just five feet from the cockpit window and the crew were in genuine fear that it was going to hit the tail of the plane. The pilot was reported as saying that it was only providence that prevented an accident, and that the UAV pilot’s actions had risked the 130 lives on board.

The CAA start the risk assessment by stating that they recognise the benefits and support the safe use and development of UAVs, so this is not a matter of us versus them. I don’t think any sensible and respectful UAV pilot would disagree that safety should always be the number one priority – no amount of great footage is worth risking lives! A UAV striking an aircraft at high speed can also cause expensive damage, and data released by the EASA (European Aviation Safety Agency) reports that a UAV strike would be structurally more damaging than a bird strike.

Some of the highlights from the CAA risk assessment are:

• Currently, there have been no actual collisions in the UK, but there have been many near-misses. There have been collisions between UAVs and manned aircrafts in other parts of the world.
• The assessment is made considering the effects a small UAV (2kg or less) could have on an aircraft.
• The drones most likely to end up in proximity to manned aircraft are smaller drones, typically of 2kg or less, flown by operators who either do not know the aviation safety regulations or have chosen to ignore them.
• The likelihood of a small drone being in proximity of a passenger aircraft when it is travelling fast enough to potentially damage a windscreen is currently observed to be about 2 per million flights, where proximity means within visual line of sight of the aircraft.
• The most susceptible crafts are small helicopters and light aircrafts, who – if struck in the windscreen by a UAV – could experience a windscreen rupture.
• Helicopters are at particular risk because of possible damage to the rotors.
• Should a small UAV strike a commercial aircraft, the risk of rupturing the windscreen is low.
• Should the UAV enter the jet engine, there is little chance of significant damage. Even if the engine was damaged, multi-engine aircrafts would still be able to fly and make a safe landing.

The CAA’s recommendations are

• The continued education of UAV pilots, so that they can operate within the regulations and guidelines set out by the CAA or other authorities.
• Define and publish geo-fenced areas to set electronic no-fly zones.
• Mandatory training and registration of UAV pilots.
• Tracking of UAVs so they can be seen in airspace by other users and allow authorities use this is take action against irresponsible UAV pilots.
• Training for pilots, so they can react appropriately in the event of a UAV collision.

The CAA and EASA will be continuing their research and monitoring but what is the best way to ensure the safety of everyone involved? While dedicated UAV enthusiasts are more than happy to follow the rules and regulations, UAVs are easily accessible and not everyone is going to have the same integrity. How do we find a solution that doesn’t hinder the responsible UAV pilot? The obvious answer is to not allow UAVs and manned aircrafts come into contact in the first place. Some newer UAVs use their GPS to detect if they are in a no-fly zone. This will mitigate a certain amount of risk, but there are ways of getting around this, so it is not a guaranteed solution.

It seems to me that the most likely cause of a mid-air collision will be either from UAV pilots deliberately flying in controlled airspace or from loss of control. The latter being far less likely as most “fly aways” or loss of control situations result in the craft losing height or striking something far lower down. Maybe we need to look into stronger penalties for those deliberately breaking the rules? Maybe we need to enforce registration on all crafts and pilots? This is a debate I will pick up on in a future article.