A new system using RF detection of drone radio transmissions to warn of incoming drones is just one of several interesting developments in the unmanned systems sector this month.
While UAS, or drones, continue to proliferate around the world, the majority appear to be used in meaningful and useful applications — earning money, helping disaster relief and in public service applications such as firefighting and police monitoring/tracking the bad guys. And there are those who fly them from the beach, just to get good overheads of the expensive neighborhood — lots of harmless, non-intrusive backyard, conscientious home-grown operations.
But every now and again some bright spark tries to get the best possible picture of a passenger jet on approach or during regular air-traffic maneuvers. Air France just cried foul on Thursday, Feb. 9, when a Boeing 777 on approach into Washington-Dulles Airport caught sight of UAV estimated to be only 100 feet above the aircraft.
Airport Close Call
Now, why would a huge 240-foot-long, 250-ton B-777 even be bothered by a skinny 10- to 15-pound baby drone? Because on approach, an aircraft is dumping lift, reducing altitude, balancing speed — maneuvering a huge beast like a 777 can be quite a delicate operation. Its huge turbofan engines are also spinning really fast even at flight idle, and they still suck in an awful lot of air, so sucking in a stray quadrotor isn’t difficult. They do test these engines for bird ingestion during qualification, but I don’t think anyone has yet put anything like a DJI drone through an engine to see if the engine survives — frozen chickens don’t have any of the hard bits that drones have — and the whirling supersonic blades inside the compressor sections will not take well to foreign objects made of plastic, fiberglass, silicon and metal. Power loss low on approach can easily lead to disaster.
Not to mention that at 700 feet, it’s probably bad news for the ~300 passengers if an engine quits or the guy driving has to unexpectedly jink the aircraft sideways to avoid a darn drone. This low-energy phase of flight involves a delicate balancing act of many parameters, and we don’t need pilots to be distracted from their focus of bringing their aircraft down a narrow landing corridor safely to the runway. Never mind the damage that even a small UAV can do to a multi-million-dollar aircraft. The Federal Aviation Administration (FAA) has mandated that drones fly below 400 feet and stay several miles away from airports for a reason.
Detection and Disabling Drones
Which brings us once again to equipment intended for the detection and disabling of drones. Keeping these pesky, unwelcome intruders away from penetrating airport protection boundaries — or other sensitive areas — is starting to become a business for which significant growth is being forecast, even paralleling the growth of drone sales.
Several significant European agencies have already put Sensofusion radar equipment to work defending their facilities, or are undertaking joint R&D efforts with the company. Installations such as prisons, government, military and community security sites have benefited from a hybrid detection and location solution system known as Airfence.
And, to the point, Sensofusion from Finland was also recently included in a group of companies selected by the U.S. FAA for a cooperative program aimed at the development of drone protection, location and prevention for airports. The other companies added to the FAA Pathfinder Program at the same time were Gryphon Sensors and Liteye Systems. The FAA’s objective is to find a system to deploy to “spot, block and drop the unwanted unmanned aircraft systems” before they get anywhere near the boundary fence, never mind into controlled airport airspace.
The Airfence system starts by using RF detection of drone radio transmissions from over six miles away and immediately raises the alarm in case of an intrusion — even notifying controllers on their smartphones. The system then triangulates the location of the incoming drone and uses what appears to be directional high-power RF transmissions to disrupt the drone’s control link.
For an example of how attention is turning to anti-drone systems, Dedrone in San Francisco, which develops software products designed to detect drones and protect high-value airspace from drone threats, recently secured a whopping $15 million during a round seeking investment funding.
Army’s Shadow Disappears
It could be that a roaming drone might not be wandering at the hands of someone intent on mischief. Operators of a $1.5-million U.S. Army Shadow fixed-wing UAV lost contact during a training flight recently, and it was presumed to have crashed in Southern Arizona within the area of operations.
The Army went looking for the bits, but extensive searches found no trace of the elusive Shadow. Turns out that the UAV was eventually found by a hiker stuck up a tree several hundred miles away in Colorado, in the foothills west of Denver. The Army sent local troops and police to recover the errant drone.
So, it seems that it’s not just malicious operators who may cause problems in commercial airspace. When things go wrong, we may also need a means to bring down an off-flight-plan drone. The side-trip for the Shadow apparently may have been brought on by unusually warm, gusty winds blowing into Colorado from the desert southwest on the day the aircraft went missing. Just as well that the tree caught the drone, as Shadows have a flight endurance of eight to nine hours.
General Atomics Seeks Non-Military Opportunities
And now General Atomics (GA) — one of the best-known UAV manufacturers of them all and their turboprop powered Predator — both are looking for opportunities in the “less-military, semi-commercial” world. The UAV that most people picture when someone says drone is probably the Predator, or its successor known as the Reaper.
GA recently announced that its new SkyGuardian UAV is intended to be certifiable to airworthiness requirements. Given that no civilian standards yet exist for this class of large UAV, GA is using published military NATO, UK and German standards and recommendations for its early certification activities. SkyGuardian has benefited from a five-year-long company-funded effort to develop a certifiable UAV. Given that the existing military Predator fleet has altogether flown for almost four million hours, GA should already be ahead of the curve when it comes to proving airframe and systems reliability. The first production aircraft is planned for 2018.
While its clear that GA is using largely military qualification standards and the target market seems to be in support of ground forces, its also aimed at non-military applications, such as border patrol, and quasi-military operations such as police, related security agencies and disaster relief. A maritime patrol version is also planned for coastal and open-water coast-guard applications. SkyGuardian has a lengthy 35-hour endurance, can fly at up to 240 mph and reach altitudes of around 46,000 feet.
And Amazon keeps pumping out patents, which give us some indication of what they might be planning for their much-publicized drone delivery system. Its latest patent has Amazon delivery drones arriving at their delivery point, but instead of landing to drop off a package, the package is dropped from the drone in flight.
To ensure that the order doesn’t land in the neighbor’s pool, the package’s descent is controlled by small parachutes, a landing flap or compressed air release. This implies that the package has radio communications with the drone, so the flying packaging isn’t inexpensive. Aerobraking, maneuvering packages — what’s next?
These flying packages or their carrier drone are not intended to interfere with commercial aircraft on take-off or approach because Amazon has also supported a drone delivery highway below 400 feet with its own air-traffic control system. But I can’t help thinking that flying packages might be a bit of a stretch. But who knows? The drone industry is demonstrating nothing but innovation!