We can fly, we can spy and we can collide: Solving the RPAS security challenge

ACUO

By Joe Urli, Brad Mason and Peter La Franchi

Lightweight remotely piloted aircraft systems (RPAS), already widely available as low cost commercial and hobbyist products, are posing a major security challenge for Australian aviation and law enforcement policy makers.

The capacity of remotely piloted aircraft systems (RPAS) to support domestic law enforcement and security applications is widely recognised as an important emerging focal point for capability planners in Australia as well as internationally. There is a darker side to that outlook however, the rising domestic security challenge of unregulated RPAS being fielded the specific intent to conduct illegal operations that range from outright acts of delinquency to criminality and terrorism.

Lest the use of RPAS in such dark ways be considered speculative, consider this: There is already legislation in place in Queensland banning the use of RPAS and hobbyist radio control model aircraft in the designated security zones being established for the conduct of the Group of Twenty (G20) summit in Brisbane in mid-November this year. The basis for that ban is obvious if the parameters of RPAS technology are understood: a proficient operator fielding an $800, four- rotor multicopter with a video camera could track a given diplomatic official from his hotel to the conference venue with the imagery helping perfect an assassination attempt. Another proficient operator, using an $8,000, eight-rotor commercially available RPAS could carry a small improvised explosive device and fly it into a selected diplomat’s car even as it sped down a Brisbane motorway.

Nor is the capacity to use commercially available UAS as a threat system restricted in any sense just to high profile diplomatic gatherings. These readily available commercial products are in fact already a very real problem from a variety of perspectives. At the end of June this year, security guards in Dublin, Ireland, discovered a crashed hobbyist-grade RPAS in a prison exercise yard; the user is believed to have been attempting to deliver contraband. Three months earlier, Victorian police arrested a man flying a hobbyist RPAS near the Melbourne metropolitan remand centre, with charges including possession of a drug of dependence.

In October 2013 a visitor from the United Kingdom flew his hobbyist grade system, brought into the country in his suitcase, around the Sydney Harbour Bridge under the cover of darkness. The RPAS crashed onto the railway lines on the Western side of the bridge deck and briefly sparked a reaction from Sydney-based counter terrorism unit. The RPAS operator was later fined by the Australian Civil Aviation Safety Authority (CASA), one of the few instances of prosecution that has occurred in Australia despite the regulator frequently acknowledging it does not have the resources to effectively monitor and oversee the breadth of this important and rapidly growing segment of aviation.

A solution, made public in May this year in the form of a proposed change to Australian aviation regulations, is the complete removal of regulatory oversight of RPAS below 2kg in weight unless they are being used for commercial purposes. Such small systems, CASA argues, are unlikely to be capable of causing harm or incidents and should therefore be treated as an evolved form of model aircraft. The proposal has generated widespread concern within the Australian aviation community, linking organisations ranging from the Australian Certified UAV Operators Association, the Australian Airports Association and the Aerial Agricultural Association of Australia in a common position of opposition.

Small Things, Big Impacts
The need for effective and common security structures as part of ensuring the safety of the global air navigation has been an essential feature of national and international air law since the 1944 Chicago Convention. The place of all forms of RPAS in that global regulatory structure is still in a state of flux, however CASA’s proposed deregulation is unique in global terms. There is no other national aviation regulatory authority in the world seeking to remove an entire class of aircraft from its oversight and indeed, if the example of the United States is considered, the Federal Aviation Administration (FAA) is seeking to expand and enhance its controls over the small RPAS segment at a broad level, even as it also moves to facilitate commercial applications.

Can lightweight and hobbyist grade RPAS pose a specific and credible threat to aviation safety? In November 2013, a hobbyist flew a small RPAS over the final approach flight path into Vancouver International airport, filmed a commercial airliner flying just beneath it, and then posted the video to YouTube. In May this year a commercial airliner landing at Perth airport in Western Australia had to take evasive action at 3800ft altitude because an RPAS was flying in its path. On 30 June 2014, Canadian police launched an investigation of yet another incident involving yet another RPAS incursion at Vancouver International.

In the United States, the FAA is investigating a series of critical incidents involving near misses near airports, the most recent being an American Airlines flight almost colliding with a RPAS on final approach in regional Florida. While the RPAS in each case were small, ingestion of the system into an aircraft engine at a critical phase of flight could cause a major crisis, and a $500 hobbyist RPAS can easily fly to altitudes of several thousand feet for tens of minutes. CASA itself released a study in early June 2014 which assessed the potential damage that a small RPAS could cause to an airliner, with this acknowledging significant damage could result in an engine ingestion scenario. The study also cautioned the regulator that more research, including trials looking at issues such as the likely consequences of a lightweight RPAS striking the windshield of a general aviation aircraft were required before any definitive safety decisions could be made. CASA has not actioned that recommendation despite its deregulation push.

While these near airport safety incidents appear largely to be the result of hobbyists flying in ignorance of aviation regulations and with common sense set aside, they flag the possibility of a more significant problem, with security at its core. Consider a scenario where multiple small systems are intentionally placed in the flight path of an airliner. To bring down a passenger flight as it closes in to land at Brisbane International, imagine a swarm of 50 modified hobbyist- category RPAS, each no more than 2kg in weight and launched from multiple park and backyards under the primary south-southwest approach. Each RPAS is programmed to fly by different routes to arrive at the same time at a single waiting point directly inside that main flight path, perhaps 8-10km from the start of the runway.

RPAS modified to act as a virtual homing beacon for other units. One leader RPAS is flown in FPV directly towards an airliner engine intake, and half the swarm follows in milliseconds. A second operator uses another leader RPAS to take out a second engine with the remainder of the swarm.

Would such a strike be detectable in its critical convergence phase by extant sensors aboard an aircraft or by air traffic control radar? For a commercial airliner the answer is clearly no, nor would air traffic control likely detect the converging RPAS because of their small size as well as their separation during all but the final seconds of flight. For a military or modified state aircraft, nose mounted radar or an imaging sensor may provide some warning but only in the final seconds of swarm convergence, directly before the commencement of impacts.

The total cost of equipment needed to mount such a terrorist action could be as low as $100,000 using nothing more than adapted existing commercial products. The lead time for a technically proficient, hostile actor to create and ready such a swarm can be reasonably estimated at less than tens of weeks. This is not an argument for outright banning of all forms of RPAS, which would be a retrograde and economically harmful step, but rather a clear pointer towards an intelligent regulatory structure of far greater sophistication than we see today.

On Terminology
The terms ‘Unmanned Aerial Vehicle’ (UAV), ‘Unmanned Aircraft System’ (UAS), ‘Remotely Piloted Aircraft System’ (RPAS) and ‘Drone’ are, in the broad, all references to one and the same thing, this being: “An aircraft (or aircraft-system) that is flown from a remote location without a pilot located in the aircraft itself.