Gatwick Airport, one of London’s five major airports and the second busiest airport in the United Kingdom, shut down its runway for over 16 hours overnight on Wednesday after sightings of one or more drones within the airport perimeter, stranding tens of thousands of passengers and disrupting flights throughout the UK with repercussions in France and the Netherlands. At 1:45PM Thursday local time, the airport announced that flights would be cancelled until at least 4PM, with disruption expected through tomorrow.
At 9:21PM local time on one of the longest nights of the year, there were multiple sightings — Gatwick spoke of two drones on Twitter — and takeoffs were halted while incoming flights were rerouted to other airports. Sightings were reported during the night. Gatwick advised passengers to check with their airlines concerning flight disruptions. The runway was briefly reopened around 3:00AM, but closed again shortly thereafter when a drone was spotted again.
Drones are considered dangerous to airplanes due to the collision risk, in particular if ingested into a jet engine. The UK Airprox Board, which reports on air proximity incidents, has seen near misses with drones rise spectacularly in the past four years. Aircraft pilots are very concerned about the risks posed by illegal drone flying; the Aircraft Owners and Pilots Association (AOPA) has worked with Dà-Jiāng Innovations (DJI), the world’s market leader in c-drones, to improve their “geo-fencing” product AeroScope used to detect and monitor illicit drone use. There is growing consensus for regulations requiring drones to emit identifiers.
Frustrated passengers unable to disembark from jets or trapped in the airport’s two terminals took to social media as the night wore on. There were unconfirmed reports of a baby being born on one grounded plane, police boarding another to calm a furious passenger, and taxis charging exorbitant rates to drive passengers between cities.
Sussex police sent a helicopter to try to find the drone or drones and its operator(s), without success, and appealed to the public for information. They said today, “It is believed that the Gatwick devices used are of an industrial specification. We are continuing to search for the operators”. The inability to locate and ground the drones highlighted the unpreparedness of Gatwick — and perhaps other airports — to check deliberate illegal flights of drones over its airspace.
UK law, updated on July 30, prohibits flying a drone without special authorization:
- within 1 km (.6 mi) of an airport
- more than 500m distant
- within 50m of people, vehicles, or buildings
- over 400 ft (122m) altitude
As of November 30, 2019, drone owners will be required to register their drones and will be required to take an online safety test. The government said last May:
Drone users who flout the new height and airport boundary restrictions could be charged with recklessly or negligently acting in a manner likely to endanger an aircraft or any person in an aircraft. This could result in an unlimited fine, up to five years in prison, or both.
NATS, the UK’s main air traffic control provider, has a website, Dronesafe, outlining these restrictions and offers a smartphone app, Drone Assist, developed with Altitude Angel of Reading, Berkshire. In March, the company announced it would work with NATS and Frequentis AG of Austria on integrating c-drone traffic (UTM for unmanned traffic management, or U-space) with commercial aviation.
The Civil Aviation Authority (CAA) said in a statement: “Given the reasons for the current disruption at Gatwick Airport, the Civil Aviation Authority considers this event to be an extraordinary circumstance. In such circumstances airlines are not obliged to pay financial compensation to passengers affected by the disruption.”
Gatwick Airport, which handled 45.6 million passengers and 282,000 aircraft movements in 2017, has a main runway and a shorter standby runway. The 40-year-old agreement barring the simultaneous use of both runways expires in 2019 and the airport recently outlined a draft master plan to upgrade the standby runway to regular use for takeoffs, as well as planning for a new runway south of the airport. A public consultation on the draft master plan is available until January 10.
Counter-drone technology exists, but regulation in the UK and other countries has not kept pace with the rapid expansion of hobbyist pilots. In February, The Center for the Study of the Drone at Bard College published a study identifying over 230 products produced by 155 manufacturers in 33 countries [PDF]. There are two aspects to so-called C-UAS (counter-unmanned aircraft systems) tools: detection, to locate a drone and its pilot if there is one, and interdiction, to ground or neutralize the drone, usually classified as passive or active (this last remains illegal in many countries, including the US, although that will change with the recent FAA reauthorization). Among the methods available are:
- video cameras, watched by human operators, suitable for smaller sites such as a building but labor-intensive, unreliable, and unwieldly for an airport
- micro-radar, to localize drones
- radio frequency (RF) scanning, to identify drones and operators, who are usually nearby
- electro-optical (EO), to automatically visually identify drones based on their shape
- infrared, to detect drones based on their heat signature
- acoustic, to identify drones based on the sound of their buzzing rotors
- radio jamming, to interfere with drone telemetry (control) and video link, the FPV (first-person view) used by pilots. This could crash the drone in an unintended area
- spoofing, the hacking of a drone’s telemetry control signal
- GNSS jamming, to block a drone from knowing its position. Drones are preprogrammed to stop movement, or land, if GPS or GLONASS signals are unavailable
- laser gun, to damage the drone, a difficult and dangerous technology to use near an airport
- firearms, shooting at a drone with ammunition
- water spray, a scaled-down version of a water cannon like those used by police against demonstrators
- EMP (electromagnetic pulse), damaging the drone’s electronics, possible at short range but ill-suited for an airport
- strobe lights, which render the FPV video feed of an offending drone unusable with flashing bright lights
- raptors, training eagles or other birds of prey to hunt drones, a labor-intensive solution with mixed results
A defense system also requires software for situational awareness and logging a drone’s movements, integrating one or more of the detection technologies listed above in a so-called layered approach. The interdiction methods can be ground-based or drone-based, for example a large hunter drone with an expert pilot could blind a target drone, then physically disable it with netting or even ram it, or a vehicle could drive to an open area near a runway and a handheld system could jam a drone’s signals. Fortem Technologies of the US state of Utah (see our interview with Gregg Pugmire) sells detection, big-picture software, and drone-based netting solutions. Dedrone Inc., with offices in San Francisco, Virginia, and Germany, also markets detection, software, and interdiction tech.