Unmanned Aerial Systems - Integrating UAS into National Airspace System

The Federal Aviation Administration (FAA) has been very careful about setting the legislation for commercial use of unmanned aerial system (UAS) for a long time, despite the fact that many other countries have already established their regulations to allow UAS operations (GAO, 2015, p.29). The main reason is that of all the safety issues concerning the operation of UAS, the ability to safely maintain proper separation from other traffic in the National Airspace System (NAS) is the most difficult to overcome (DOT, 2013). To FAA, any unmanned aerial vehicle (UAV) has to be able to demonstrate a high level of robustness in terms of its ability to “sense and avoid” other air traffic. As required by Section 332(a) of the FAA Modernization and Reform Act, US. Department of Transportation has released a UAS comprehensive plan to ensure that all commercial airborne UAS are equipment with “Sense and avoid” capabilities (FAA, 2013). “Sense and Avoid” is necessary to achieve autonomy (Yu & Zhang, 2015) and can be achieved via two methods, airborne sensing and ground sensing (Zeitlin, 2010). Airborne sensing will make use of sensors on board the UAV to detect and avoid obstacles, whereas ground sensing makes use of ground radar and other sensors to relay air traffic to the UAV for it to maintain separation from other air traffic. However, airborne sensing requires expensive on-board sensors which can be heavy and consume significant energy. Ground sensing on the other hand, has to be present in the entire operating area of the UAV, making it impractical for long distance flights. 

According to Fasano et al. (2015), the two functions to have separation assurance and to be able to make extreme manoeuvres are key to good “sense and avoid”. Having airborne surveillance for separation assurance and collision avoidance is the ultimate goal of a UAS system and can be achieved using cooperative instruments such as transponders to broadcast and interrogate, and non-cooperative sensors such as Traffic Collision and Avoidance System (TCAS), which has an advantage in case of an air-to-air radio link loss. FAA (2016) states that there are three types of UAS operations: public; civil; and model aircraft. For civil use, special airworthiness certificate can be applied under experimental category; type and airworthiness certificate under Restricted category; and certificate of wavier or authorization under commercial category (FAA, 2016).

Accelerating the use of UAS in commercial applications will provide economic and social benefits. The future of UAS integration into NAS depends upon the pace of FAA development of a comprehensive regulatory framework, which has some urgent need to catch up with the fast developing UAS technologies.

Reference

DOT (2013). Unmanned Aircraft System (UAS) Service Demand 2015-2035: Literature Review & Projections of Future Usage. Retrieved from https://fas.org/irp/program/collect/service.pdf

Fasano, G., Accardo, D., Tirri, A. E., Moccia, A., & De Lellis, E. (2015). Radar/electro-optical data fusion for non-cooperative UAS sense and avoid. Aerospace Science and Technology, doi:10.1016/j.ast.2015.08.010

FAA (2013). UAS comprehensive plan: A report and the Nation’s UAS path forward. Retrieved from http://www.faa.gov/about/office_org/headquarters_offices/agi/reports/media/UAS_Comprehensive_Plan.pdf

FAA (2016). Unmanned aircraft systems: Frequently asked questions. Retrieved March 30, 2016 from https://www.faa.gov/uas/faq/#qn4

GAO (2015). Unmanned aerial systems: FAA continues progress toward integration into the National airspace. Retrieved from https://fas.org/irp/program/collect/gao-15-610.pdf

Yu, X., & Zhang, Y. (2015). Sense and avoid technologies with applications to unmanned aircraft systems: Review and prospects. Progress in Aerospace Sciences, 74, 152-166. doi:10.1016/j.paerosci.2015.01.001

Zeitlin, A. D. (2010). Sense & avoid capability development challenges. IEEE Aerospace and Electronic Systems Magazine, 25(10), 27-32. doi:10.1109/MAES.2010.5631723

UAS Strengths and Weaknesses

There has been a growing need for the use of unmanned aerial system (UAS) in civilian applications. Decades ago, UAS development had been largely driven by military applications and only been deployed for military use, such as in Vietnam, Iraq and Afghanistan conflicts. Radio technology then had enabled unmanned flights using altimeter, gyrocompass and later with GPS technology in stealth-based three dimensional thrust vectoring flight control and advanced avionics. There are numerous applications of UAS such as security, search and rescue, monitoring, disaster management, crop management, survey and communications (UAVSA, 2016). However, the Federal Aviation Administration (FAA) has prohibited the use of UAS for commercial purposes, except for certain specific activities such as in law enforcement and disaster management. As at September 2015, 1400 of such exemptions had been granted for agricultural, real estate, film and broadcasting, oil and gas, and construction activities (Canis, 2015). Legislation aside, the biggest strength in the use of UAS lies with the fact that they are able to be operated in hazardous conditions, such as extreme heat, darkness, hostile enemy environments, etc. that would have otherwise pose significant risks to pilots in manned aircraft.

The Scan Eagle X200 and Puma RQ-20A were the two UAS platforms approved by FAA for commercial use in 2013, mainly for aerial surveillance. Later in March 2015, FAA approved the use of drones below 200 feet of altitude for those companies who had already obtained approval after going through the ‘Section 333’ process (Dillow, 2015). The Puma was originally used by military and government agencies to conduct intelligence, surveillance, reconnaissance and target acquisition (ISRT), battle damage assessment, maritime patrol, search and rescue and drug interdiction missions over water or land. The system can be launched by hand and has ground control stations (GCSs) that can receive live imaginary from the UAS payloads and process data in real time for interested parties. The GCS can also be used by the firm’s own Raven and Wasp/BATMAV systems. The strength of the Puma is that it is highly portable, requiring only two people to operate. It can be set up within five minutes for it to operate with a range of 15 km for an endurance of 2 hours (AeroVironment, 2016). Unlike for any defence organizations where cost is the least of a concern due to the paramount importance of national security, at a price tag of about $250,000, Puma AE system can be a significant cost if it is to be acquired and deployed for civil use.

In general, UAS used in military has significantly higher costs compared to those required by civil missions. Endurance and range are important factors so that the UAS can be launched far from enemy territory. Operating flight ceiling has to be large enough to avoid detection or getting destroyed by the enemy. For aerial surveillance at high altitudes with good endurance and range, the UAS will need to have expensive and complex payloads, GCSs and manpower to provide for all these requirements. Civil applications using UAS may not have these same requirements during aerial surveillance. Applications such as monitoring forests for illegal logging, wildlife observation or monitoring illicit drug trafficking can be performed using UAS platforms at a much cheaper cost of less than $10,000. Where designs are concerned, the other platforms can also be easily deployed at a much lower cost.

UAS usage is expected to proliferate over the next decade. As such interest grows, there should be significant investments into this market, both military and civil, to cater to a wider scope of applications. If the authorities continue to relax their policies to encourage more UAS use into future civil applications, we can expect to see more cross-sharing of knowledge between military and civil groups in this technology, and with multiple correlation of missions between them, will certainly bring about more unique and advanced technological improvements.

Reference

Aerovironment (2016). The Puma AE Datasheet. Retrieved from http://www.avinc.com/downloads/PumaAE_0910.pdf

Canis, B. (2015). Unmanned aircraft systems (UAS): Commercial outlook for a new industry. Congressional Research Service. Retrieved from https://www.fas.org/sgp/crs/misc/R44192.pdf

Dillow, C. (2015). FAA issues blanket approval for commercial drone use below 200 feet. Fortune. Retrieved from http://fortune.com/2015/03/24/faa-commercial-drone-approval/

UAVSA (2016). Civil and commerical UAS applications. Retrieved from https://www.uavs.org/commercial