ASCI 530 Blog Post 4: UAS Missions - Disaster Response

Military support from active and national guard forces is critical for disaster response efforts, as it allows civil entities access to manpower and equipment normally reserved for defense. Specifically, Combat Search and Rescue (CSAR) forces can be leveraged to find, recover, and treat distressed persons, which was used extensively following Hurricane Katrina. The Air Force alone generated over 1,700 airlift, strategic reconnaissance, and rescue helicopter sorties for the recovery effort (Ball, 2016). An absent capability was tactical reconnaissance, which could have been used to efficiently identify and prioritize victims, and provide locations for rescue crews. With several National Guard units converting to various Unmanned Aerial Systems (UAS), this capability could be included in future domestic disaster relief efforts.

Figure 1. US Air Force CSAR unit recovers flood victims from a rooftop. Reprinted from Air Force Reserve Command Citizen Airman Magazine, 2005.

The Mission

Tactical reconnaissance, in the context of disaster response, provides area searches, precise point-of-interest geolocation, and continuous near-realtime intelligence. It also involves networking with command centers, directing rescue assets to victims, and surveying helicopter pickup zones. Specific tasks for a UAS include:

• Systematic area searches from low to medium altitudes, using infrared (IR) and electro-optical (EO) sensors to determine the location, disposition, and trend of stranded victims with high fidelity.
• Returning full-motion video high-rate synthetic aperture radar scans to provide realtime status of victims or difficult to observe situations like chemical fires or potentially explosive material.
• Using the communications reach-back inherent in UAS to maintain tactical command and control of rescue assets, direct helicopters to victims, and act as a radio relay.

System Selection

The Boeing-Insitu ScanEagle, General Atomics MQ-1B/C, and General Atomics MQ-9A will be analyzed for suitability in the disaster relief mission. All three systems have been extensively used by the US military, providing a large body of experienced operators and proven track record that can hopefully ease certification for use in the National Airspace System (NAS). The ScanEagle is flown via Line-of-Sight (LOS) control only, whereas the other three can be flown via either LOS or Beyond-Line-of-Sight (BLOS) control.

The ScanEagle is a 49lb low altitude vehicle that is launched with a catapult and recovered by a SkyHook (crane with wire that is snagged by wingtip-mounted hooks). It boasts 24 hour endurance with a cruise speed of 50-60 knots (Insitu, 2015). The payload bay currently accommodates a single EO or IR sensor (dual sensor in development). The ScanEagle range is limited to 62 miles by the LOS data link, meaning that it will have to be transported to a launch/recovery site close to the disaster, losing precious time. The ScanEagle’s lightly loaded, high aspect ratio wing is also highly responsive to turbulence (Austin, 2010), which may be undesirable in the wake of a major meteorological event.

The MQ-1 Predator B and C are medium altitude aircraft weighing 2,200lbs and 3,600lbs respectively (General Atomics, 2016). Both carry a large multi-spectral sensor turret for searches in all lighting conditions. The turrets also include eye safe laser markers that can be used to guide night vision-equipped rescue helicopters to distressed persons, a capability that would have proved useful during the first eight days of Katrina recovery where crews operated around the clock (Ball, 2016). The MQ-1 provides up to 30 hours of endurance and BLOS datalinks allow it to be flown from home base to a disaster area, at a cruise speed of 150 knots to respond quickly.

The MQ-9A Reaper is another medium altitude UAS, weighing over 10,500lbs and bringing similar sensor technology as the MQ-1 (General Atomics, 2016). While the Reaper nearly doubles many MQ-1 performance parameters, it will not significantly enhance the rescue mission. It also requires longer runways and additional support equipment, making it more difficult to forward-deploy than the ScanEagle or Predator.

The MQ-1 Predator is the recommended choice for disaster response in suitability and number, with the Air Force and Army maintaining domestic fleets for training. Additionally, the Army has equipped 10 divisions with MQ-1Cs, adding flexibility through geographical coverage (US Army, 2016).

Legal and Ethical Considerations

The most glaring issue for domestic employment of military MQ-1s is legal, and may appear to be a violation of Title 18 United States Code (USC), Section 1385, commonly known as the Posse Comitatus Act (PCA). Under Title 32 USC, a state governor can “call forth the militia” to respond to civil emergencies and that those forces are not subject to PCA (Elsea & Mason, 2008). This implies that UAS operated by the National Guard (Army or Air Force), as authorized by the Governor, are exempt from PCA. Federal military forces can be legally committed for search and rescue operations under Title 42 USC, Section 5121 (Stafford Act) at the request of the affected state governor. Additionally, Congress has issued standing guidance to the Department of Defense (Title 10 USC, clause 371-382) to share information and equipment with civilian authorities. With this relatively permissive application of the law, ethical concerns may arise with the use of military surveillance aircraft in the NAS. Component commanders need to ensure that UAS operators are not inappropriately using sensors to collect information on citizens and/or property for personal use, or explicitly for criminal prosecution. In the case of the latter, UAS crews scanning private property during recovery efforts shall not devolve into illegal searches under the PCA, or record data for future use.

Conclusion

This short essay has defined a civil use for military UAS, providing three core tasks of search, victim location sharing, and networking. Three platforms were considered, and the MQ-1 (B or C) was selected as the most suitable for disaster relief efforts due to long loiter time, resistance to moderate meteorological phenomena, and relatively small logistical footprint. The legal implications of employing military UAS in support of civil disaster response were analyzed and found to allow their operation. Ethical conduct of such operations was also discussed, with risks mitigated by guidance from component commanders.

References

Austin, R. (2010). Unmanned aircraft systems: UAVs design, development and deployment. Reston, VA: American Institute of Aeronautics and Astronautics.

Ball, G. (2005, November 3). Hurricane Katrina Relief Operations. Retrieved August 22, 2016, from http://www.afhso.af.mil/topics/factsheets/factsheet.asp?id=18651

Elsea, J., & Mason, R. C. (2008). The use of federal troops for disaster assistance: Legal issues (United States). Washington, D.C.: Congressional Research Service, Library of Congress. Retrieved from www.dtic.mil.

General Atomics Aeronautical Systems. (2016). Aircraft Platforms. Retrieved November 22, 2016, from http://www.ga-asi.com/aircraft-platforms

Insitu. (2015). ScanEagle Product Card. Retrieved November 22, 2016, from https://insitu.com/images/uploads/pdfs/ScanEagle_SubFolder_Digital_PR080315.pdf

United States Army. (2016). MQ-1C Gray Eagle Unmanned Aircraft System. Retrieved November 22, 2016, from http://asc.army.mil/web/portfolio-item/aviation_gray-eagle-uas/

ASCI 530 Blog Post 3: UAS in the NAS

As Unmanned Aerial Systems (UAS) become more prevalent in the United States, a safe and effective method of National Airspace System (NAS) integration is needed to prevent stifling the new industry. The method should include Group 1 through 5 UAS and all varieties of aircraft configuration.

Figure 1. US Department of Defense UAS group descriptions. Reprinted from DoD UAS Airspace Integration Plan , by the UAS Task Force, 2011.

Understanding the Problem

The Federal Aviation Administration (FAA) is charged with maintaining control of the NAS, and does so with operating regulations, operator qualifications, and airworthiness certifications (FAA, 2016). The Department of Defense (DoD), commercial, and public research entities require access to the NAS for numerous missions, however FAA regulation has lagged UAS industry growth, creating a roadblock for many military and civil operations. The root of the problem lies in safe traffic separation between manned and unmanned aircraft, all with a wide variety of equipage standards. In airspace classes A and B, responsibility for separation lies with air traffic control (ATC) using primary and secondary radar systems. In airspace classes C through G, a UAS will face the challenge of integrating with optionally or non-participating aircraft. Instrument or visual flight rules (IFR or VFR) overlay additional considerations. Under IFR, aircraft are separated by positive (ATC personnel) or procedural control (published departure, arrival, or approach procedures). Under VFR, pilots are responsible for their own separation, optionally participate with ATC depending on the airspace class, and are the most challenging airspace user for UAS to share with. The following solutions encapsulate a phased approach that starts with systems technologically closer to NAS access and working towards full UAS access.

IFR Solution

This solution is most readily implemented with Group 4 and 5 UAS, as many of them already meet (or have the space and power available for) the IFR equipment requirements in Federal Aviation Regulation (FAR) 91.205 (FAA, 2009). Medium and high altitude UAS would transition to Class A airspace using procedural control measures (such as a climb corridor) recommended by the DoD UAS Integration Task Force (2011) that would separate non-participating manned aircraft by charting the control measures as special use airspace. Once above FL180, UAS would not differ from manned aircraft in operation or control. One UAS specific condition is loss of command and return links. Large UAS have robust lost-link programming capabilities which would be leveraged to maintain the aircraft in a safe and predictable state. In the terminal environment, lost-link UAS would follow a predetermined path similar to a missed approach procedure. During en route phases, lost-link UAS would follow either a path provided in a procedure similar to a Standard Terminal Arrival, or fall back on the same guidance for manned aircraft that lose contact with ATC (maintain last assigned, then expected, then filed). In any case, the burden of ensuring safe lost-link separation would rest with an appropriately trained and certified UAS pilot. This IFR solution has the benefit of requiring very little aircraft modification, can be implemented with today’s technology, and allows large UAS to access the NAS soonest in order to accomplish critical missions and begin adding to the collective knowledge base. The costs are increased workload on air traffic control, administrative functions to create the procedures given above, and establishment of additional Class B airspaces in areas with high UAS traffic.

VFR Solution

A VFR solution would allow UAS access to all airspace classes in the NAS, but is the most difficult to implement technologically. Significant research has been done to allow UAS to satisfy the “see and avoid” FAA requirement for VFR flights. The most successful to date has been demonstration of autonomous and pilot directed collision avoidance using a fusion of Automatic Dependent Surveillance-Broadcast (ADS-B), Traffic Collision Avoidance System (TCAS), and onboard air-to-air radar. This allows separation from close range TCAS-equipped aircraft, close range ADS-B/Out-equipped aircraft with onboard ADS-B/In functions, and non-participating aircraft. Additionally, a UAS equipped with a Universal Access Terminal would receive traffic and weather data from ground stations, adding redundancy. The only shortfall of such an all-inclusive system is the cost in size, weight, and power supply which would exclude Group 3 and below vehicles. UAvionics has marketed a micro ADS-B receiver weighing only 1.5 grams that provides autopilots or ground control stations with participating traffic information within 100 miles (sUAS News, 2016). The most promising solution for separating light UAS from non-participating traffic lies in vision based systems that combine multi-spectral sensors with image processing algorithms to detect moving objects (Novik, 2014). The challenge vision based systems will face is providing the same detection probability as a human pilot in an extremely wide range of ambient lighting and atmospheric conditions. For Group 1 UAS, even vision systems and micro receivers may impose an unacceptable sacrifice in payload. Since they weigh less than 20lbs, a risk analysis should be conducted to determine the probability of collision with manned aircraft and whether the consequences would exceed that of bird strikes.

Conclusion

This short essay has defined the challenging problem of operating manned and unmanned traffic in the NAS in the context of airspace classes and flight rules. The DoD is poised to access the NAS with large UAS, as it has established internal practices to satisfy the technology, training, and certification needed for integration. Rapid integration of these assets will not only accomplish vital defense, training, and disaster response missions, but pave the way for commercial and public operations. Technical solutions for lightweight UAS were summarized, along with the inspiration to conduct risk analysis, since a 100% perfect solution may not be required and will likely constrain development.

References

Federal Aviation Administration. (2016). National Airspace System. Retrieved November 10, 2016, from http://www.faa.gov/air_traffic/nas/

Federal Aviation Administration. (2009, August 21). Federal Aviation Administration. Retrieved November 10, 2016, from http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFar.nsf/FARSBySectLookup/91.205

Federal Aviation Administration. (2016, May 10). Equip ADS-B Research. Retrieved November 11, 2016, from https://www.faa.gov/nextgen/equipadsb/research/

Merlin, P. (2015, January 25). NASA, FAA, Industry Conduct Initial Sense-and-Avoid Test. Retrieved November 11, 2016, from http://www.nasa.gov/centers/armstrong/Features/acas_xu_paves_the_way.html

Novick, D. (2014, January). Image Processing Primer Document for Autonomous Vehicle Competitions. Retrieved November 11, 2016, from http://www.robotx.org/

SUAS News. (2016). UAvionix Introduces Micro ADS-B Receiver For Small Drone Collision Avoidance - sUAS News. Retrieved November 11, 2016, from http://www.suasnews.com/2016/04/43057/

UAS Task Force. (2011, March). (United States of America, Department of Defense, Airspace Integration Integrated Product Team). Retrieved November 7, 2016, from http://www.acq.osd.mil/sts/docs/DoD_UAS_Airspace_Integ_Plan_v2_(signed).pdf