Risk of causing even more embuggerance is high, we repeat: high
Comment As the Gatwick drones chaos rolls on, with the airport now set to reopen at 8pm UK time at the earliest*, many people have been asking a simple question: why the hell can’t the authorities just shoot down the offending drones?
Like all simple questions, the answer is complex. Counter-drones tech is a new field and not quite as easy as you might imagine.
The most obvious solution is to shoot down the drones using a rifle or a shotgun. Here the problem is simple: a rifle bullet fired upwards travels a very long way if it doesn’t hit its target, or passes through it. If you’re using a.308″/7.62mm rifle pointed upwards at 70 degrees, the dangerous zone in front of it where the bullet could land is up to 2.5 miles or four kilometres long.
Current police issue rifles tend to fire .223″/5.56mm rounds, which can still travel up to 8,000ft (1.5 miles, 2.4km) high if fired at 70 degrees.
Are the police going to evacuate a 2.5-mile strip of West Sussex so they can go all Dirty Harry on the drones? Of course not.
What about a shotgun? This is far more likely than using a rifle. The danger zone for a shotgun firing the usual shot pellets is about 390 ft, or 120 metres, long, according to Blighty’s Ministry of Defence. Unfortunately, there’s no guarantee that once shot, the drones will land on the spot. A partial hit could send the drones flying off to crash on someone’s house (the town of Crawley is next to Gatwick), or leave bits of the drones lying around on the airfield – ready to be sucked into a jet engine. Far from ideal.
It also depends where the drones are flying. If it is not flying directly over the airfield, you would need the landowner’s permission to start shooting at it – as well as the permission of every other landowner that both the bullet/shotgun pellets might pass over on their way to the drone, and for good measure the permission of whoever might be the lucky recipient of the spent bullets or shot as they fall to earth. A faff, but not impossible.
Judging by police reports that the drones are “of an industrial specification”, it could be that we’re dealing with something like a DJI Matrice or an Aeryon Skyranger – larger than your average kid’s toy (or a DJI Phantom, for that matter). Shotgun pellets lose energy rapidly: if the drones is flying at a few hundred feet above the ground, it might be the case that it’s outside effective shotgun range.
The next thing you could do is jam the command signals controlling the drones. Is that doable?
Doable? Yes. Practical? Not really. Fraught with danger? Oh yes.
It’s also illegal.
No, really. Assuming the local police even have access to spectrum analysis equipment that allows them to find what frequency is being used to control the drone, they need legal permission to start broadcasting jamming signals.
