Protesters have been flying drones at Heathrow airport in an attempt to cause disruption.
Prof Ian Poll, Emeritus Professor of Aerospace Engineering, Cranfield University, said:
“I am more than happy that there are exclusion zones around airports and that there are severe penalties for those who deliberately flout the law.
“However, the regulations are written for law abiding people and my concern is that they apply to all drones and other radio-controlled model that weigh more than 0.25kgs. This captures children’s toys and hobbyists model aircraft.
“The CAA’s own assessment of risk, CAP 1627 “Drone Safety Risks: an assessment” puts the probability of an accidental proximity incident between a passenger aircraft and a drone weighing less than 2kgs, when the aircraft is travelling fast enough to potentially damage a windscreen at 1 in 500,000. The likelihood of a collision is obviously smaller and a collision would not necessarily imply serious damage. Therefore, the likelihood of a drone causing a cracked windscreen, a dent in the structure or being ingested into an engine is lower still. Windscreens and engine response to ingestion are well covered by regulation and so even if it happened there is still a significant “designed in” safety margin before lives would be at risk. Therefore, the probability of a risk to life caused by a small drone is likely to be below 1 in 10 million.
“Therefore, the suggestion, implied in the current regulations, that a child’s toy could bring down an airliner and, hence, require an airport to be closed is, in my view, a bit of an exaggeration.
“The real problem lies with the heavier (greater than say 2kg), more complex and more costly drone systems. These are increasingly being used for commercial purposes and clearly pose more of a threat to aviation than a child’s model helicopter. My own view is that these industrial sized drones should be highly regulated and not available to the general public. If this was the case then protest groups could not shut down airports with toys flown at shoulder height.
“Finally, just for context, an adult Red Kite weighs about 1kg and can reach significant altitudes. Ingesting one of these might stop an engine. However, I don’t see airports being closed down because a couple of Red Kites have been spotted within the 5 km zone.”