Gatwick closed (mod note post 1)

Sky News just reporting that it's due to the presence of 2 drones over the airport. Hope they manage to catch whoever is responsible.

I just sat through an interview with a UK Minister on Sky News, and the level of ignorance about the capability of a modern drone, and how to deal with it, was mind numbing.

You can have all the legislation you like, and work with drone manufacturers to put in systems to prevent them flying in restricted areas, and it will do NOTHING to resolve the real issue, which is that it is technically totally feasible to launch a drone from a remote location, which will then fly under programme control to a pre programmed flight plan, and the only thing that limits how long that flight lasts is the capacity of the on board batteries. There is no requirement for a ground to air radio link to control it, so there is no easy way to triangulate where the operator is, there is no uplink active.

The electronics to enable this sort of autonomous operation are freely available from multiple suppliers, and so it the software, and it is incredibly cheap to get, and the accuracy that can be achieved with the right equipment is the accuracy of the GPS signals that are used to provide the guidance.

The only thing capable of taking out such a drone will be a very directed Laser style device that will either overload the internal electronics, or cause significant damage to the mechanical parts of the device and render it incapable of continuing to fly, but if such devices are available, they are not being widely talked about, and are certainly not being deployed to the airport operators. Another possible option is to have a directional radio beam that will block GPS signals, but that will only disrupt the navigation of the device, not prevent it from continuing to fly. The problem with disrupting the GPS system to take out a drone is that there are then major problems for aircraft in the area, as they are very likely to also be relying on GPS signals for their navigational accuracy, so for obvious safety reasons, the airspace has to be cleared before a take down system can be used.

Shooting down using traditional weapons is not an option, the potential for injury or worse to third parties at a considerable distance from the airport makes any sort of projectile weapon an impossible solution, and depending on the size of the drone, even aiming such a device would be incredibly difficult to do.

And to make it clear, the potential for damage to an aircraft from a drone is much higher than from a bird, and we've seen on a regular basis the sort of damage that a bird causes.

The mass of the drone is higher, and the density of some of the parts means that they have the potential to inflict much more damage to critical components such as the engines. Fortunately, even with all the technology available, it is still incredibly difficult to put a drone into exactly the right position to impact an airframe in the right place to do damage, because of the closing speeds of the aircraft with the device.

I'm under no illusions, for a person with the motivation, it is incredibly easy to get access to the devices and the technology to cause a huge amount of disruption, and the regulators have been very slow to develop appropriate counter measures that can mitigate the problem. Having said that, the final approach to landing is a problem area, because the way that the aircraft is flown means that it is operating within a very small airspace window, so it is much easier to get the drone into a location where it has the potential to do damage.