ASCI 638, Module 3: UAS Integration into NextGen

         The goals of the FAA’s Next Generation Air Transportation System (NextGen) are to provide air traffic controllers with better tools, provide pilots with more access to information in the cockpit, and provide airlines with improved routes that are more efficient (FAA, 2017). Future aviation operations will be more integrated, with improved methods of communication and sharing of information. One objective in improving communication technology is to provide more data to pilots in the form of digital information from ATC. Flights can take more direct routes based on GPS guidance. A second communications objective is to enable Voice over Intranet Protocol for secure communication to pilots without relying on radio line of sight. 

As the FAA works to improve automation for ATC and manned aviation through technological innovation, UAS are uniquely situated to integrate into the NextGen airspace system. The command and control datalinks are digitally transmitted, with automation integrated into nearly every level of UAS technology. Specifically, the NextGen use of digitally transmitted flight clearances could be developed for UAS to automatically follow a clearance from ATC. Additionally, in the event of lost link, ATC could know instantly, and obtain a digital lost link flight plan to coordinate with area traffic. An issue with operating UAS in the NAS is the necessity for communication with ATC, which is currently achieved through line of sight radios. The NextGen VoIP communication system will enable ATC to communicate directly to UAS pilots without needing to carry a communications relay package on the aircraft, which could be costly, both in lost payload capacity and in price. Automatic Dependent Surveillance – Broadcast (ADS-B) is also a technology that could be used for situation awareness in the event of a UAS lost link. Aircraft equipped with ADS-B In can receive transmissions from other aircraft that include location, heading, and airspeed, and a UAS in lost link condition could add that information to the ADS-B message, similar to the current practice of squawking 7600 for no radio power, or 7400 for UAS lost link.

Detect, sense, and avoid (DSA) technology is also a high priority for integration of UAS into the NextGen NAS, although it is a highly specific solution to integration in the NAS. Collision avoidance can be obtained through increasing levels of safety: flight procedures and ATC separation are operational techniques to separate manned aircraft from UAS. In share airspace however, more direct surveillance is necessary, such as ATC ground surveillance. This would also begin to necessitate equipment installations into UAS, because the ATC surveillance system depends on transponder replies to provide aircraft location and altitude (Rosenkrans, 2008). With additional equipment, UAS may integrate directly into collision avoidance systems already in use by manned aircraft. ADS-B provides a lower level of safety than Traffic Collision Avoidance Systems (TCAS) II, which provide coordinated resolution advisories (climb or descend) to aircraft equipped with TCAS II transponders. The ultimate challenge is to integrate UAS into airspace with manned aircraft that may not have the above equipment installed or fully functional. DSA technology has been tested using the concept of “sensor fusion,” using multiple sources of information to create a picture of the air traffic around a UAS and avoid collision. NASA successfully tested a sensor fusion system on their Ikhana UAS in a 2015 program, conducting 170 “encounters” and obtaining over 50 hours of data using combined visual cameras, ADS-B transponders, and TCAS II (Merlin, 2015).

One of the most notable human factors issues with integrating UAS into the NAS is the design of ground control stations. In the early 2000’s, GCSs were designed for specific UAS and fielded quickly. Even with a couple of decades of experience, not much has changed. The UAS GCS removes all but a few sources of sensory input. If UAS are to be successfully integrated into a complicated and dynamic NAS, standards for GCS design should reflect previous research and standards developed for manned cockpits and immersive UAS GCS.

References

Federal Aviation Administration. (2017, February). Delivering NextGen. Retrieved from https://www.faa.gov/nextgen/delivering/

Merlin, P. (2015, January). NASA, FAA, industry conduct initial sense-and-avoid test. Retrieved from https://www.nasa.gov/centers/armstrong/Features/acas_xu_paves_the_way.html

Rosenkrans, W. (2008, July). Detect, sense, and avoid. AeroSafety World, pp. 34-39. Retrieved from https://flightsafety.org/wp-content/uploads/2016/12/asw_july08_p34-39.pdf

ASCI 638, Module 2: UAV Factory Portable Ground Control Station

UAV Factory is a Latvian unmanned aircraft systems (UAS) developer founded in 2009, focusing primarily on building small composite fixed-wing aircraft such as the Penguin line of UAS. UAV Factory also features a line of intelligence, surveillance, and reconnaissance (ISR) payloads under the name Octopus ISR Systems (UAV Factory, 2016). They announced availability of a second-generation off-the-shelf portable ground control station (GCS) in January 2012 (Mortimer, 2012). The GCS is based in a ruggedized transportation case that opens to reveal a modular electronics compartment with a docking station for a Panasonic CF-31 Toughbook (not included), a second digital 17-inch touchscreen display, storage for accessories and peripherals, and power and connection ports for datalink equipment. An interesting feature is the various power supply options that accept between 10 and 32 volts DC, including two Makita BL1830 lithium batteries (yes, the power tool company) that can be swapped out without requiring the GCS to be shut down or restarted (UAV Factory, 2016).

Because the UAV Factory GCS is designed to be modular, portable, and customizable, some of the human factors concerns will depend on the user’s selection of hardware such as pointing devices (i.e. trackballs or touchpads) and aircraft or payload controls (i.e. joysticks or gamepads). This discussion will be based on two negative factors with the GCS itself, regardless of user configuration.

The first is an issue with the included 17-inch display. Technical documents and marketing material did not specifically mention the supplier. Images in promotional material show a very glossy surface of the display, which would lead to a high level of glare when used in an outdoor environment (see Figure 1). Glare can be caused by sunlight if used in an outdoor environment, and interior lights if used indoors. The worst effect of sunlight on flat panel displays is the “reduction of display contrast” when the light illuminates both the background of an image and the contrasted shade or coloring (Rash and Manning, 2003). To avoid glare from outdoor or indoor light sources, a recommended solution would be to install a simple folding glare shield made of dark material that could shield the displays from above and beside. Additional shading would likely be required if operating outdoors on a sunny day, but a dark glare shield would greatly reduce the amount of direct light on the screen.

Figure 1. UAV Factory GCS assembly, from http://www.uavfactory.com/product/16.

The second issue is the integration of the Panasonic Toughbook in an inset manner that places the keyboard on an even plane with the work surface. This places the keyboard in a vulnerable position for being bumped or accidentally pressed while moving around the workspace, especially when intercom or datalink cables are connected and routed around the GCS. In 2011, an MQ-8B Fire Scout UAS flying from Naval Air Station Patuxent River, MD lost link with the GCS and began flying towards restricted airspace around Washington, DC. Control was regained before drastic measures were required, but the incident was traced to an accidental press of the keyboard spacebar from an operator’s headset wire, which initiated a self-destruct procedure (Fox News, 2011). A similar event could easily occur with the design of the UAV Factory GCS. A recommended measure would be to install a shield around the perimeter of the keyboard that would create an “inset” for the keys and provide a layer of separation between the keyboard and items that could accidentally rest on top of it (i.e. manuals, checklists, wires, operator’s arms, etc.).

A similar issue can be seen with the design of the Airbus A380 and A350 cockpits, which include a fold-out keyboard and trackpad (Ferhm, 2015). However, this issue is mitigated by delegating the functions of the keyboard to the electronic flight bag to access maps and charts, not essential aircraft functions. Input to the aircraft Flight Management System is made through a smaller keypad and trackball located on the center console (Ferhm, 2015).

References

Fehrm, B. (2015, June). Airbus A350 cockpit compared to A320/A330. Retrieved from https://leehamnews.com/2015/06/01/airbus-a350-cockpit-compared-to-a320a330/

Fox News. (2011, July). Single keystroke nearly self-destructs unmanned Navy copter. Retrieved from http://www.foxnews.com/tech/2011/07/18/single-key-stroke-nearly-leads-unmanned-navy-copter-to-self-destruct.html

Rash, C.E. and Manning, S.D. (2003, September). On the flight deck, lighting must satisfy a variety of needs. Flight Safety Foundation Human Factors & Aviation Medicine, 50(5). Retrieved from https://flightsafety.org/hf/hf_sept-oct03.pdf

UAV Factory. (2016). Portable ground control station. Retrieved from http://www.uavfactory.com/product/16

Advances in UAS Traffic Managment

NY works with NASA to develop UAS traffic management system

Patrick C. Miller, UASMagazine, November 17, 2016

This article informs my opinion that a large advancement in UAS technology in the near future will not necessarily come via specific technology, but rather the industry-wide standards to support it. The proliferation of unmanned aircraft technology has led to some very fascinating developments in recent years, which leaves many observers of the UAS industry wondering what could possibly be next. Aircraft systems are increasing sophistication while decreasing size, which opens up an area with high growth potential: integrated air traffic control systems. Providing a new or safer perspective is only a portion of the benefit of operating a UAS; a true benefit to UAS operations is the ability to fly beyond visual line of sight (BVLOS). However, without the ability to “sense and avoid” (S&A) other aircraft and obstacles on the ground, the safety of UAS flight cannot be completely guaranteed. Manned aircraft rules in the U.S. require pilots to “see and avoid other aircraft,” regardless of operating under visual or instrument flight rules (Yodice, 2015). Enter automated traffic management systems. In November 2016, the state of New York announced a $30 million investment that will be coordinated by the Griffiss International Airport UAS test site in Rome, NY, with intent to develop a traffic management system to control UAS flights along a 50-mile corridor between Rome and Syracuse, NY (Miller, 2016).

Developing a common air traffic control system means that all of the aircraft sharing the airspace must meet certain technological standards. In the case of the NY control corridor, NASA is working with industry partners to develop the technology to bring UAS traffic management into reality. NASA standards are based on Technology Capability Levels (TCLs), and a real-world UAS control corridor would be the next step in development (TCL 2).

Another set of technological standards is in work by the Radio Technical Commission for Aeronautics (RTCA) special committee for UAS minimum aviation system performance standards (MASPS) (SC-203). The committee consists of subsystem working groups, one of which is focused on the standards for the development of S&A technology. By demonstrating conformance to a standard, UAS system developers can accomplish most of the work towards satisfying a safety case for their system, especially when seeing integration into controlled airspace (Zeitlin, 2010).

A different approach with the same goal of automated UAS airspace integration is ongoing in the United Arab Emirates (UAE), in a direct collaboration between Nokia and the UAE General Civial Aviation Authority (GCAA). The difference is that Nokia is working directly with the

With successful implementation of NASA/FAA teaming for the advancement of a traffic management system, along with industry adoption of RTCA standards, the next 5-10 years will potentially see a large increase in BVLOS flights by UAS of all sizes. This will only occur when ground-based traffic management systems operate in concert with UAS that meet industry and regulatory technological standards.  

References:

Miller, P.C. (2016, November). NY works with NASA to develop UAS traffic management system. UAS Magazine. Retrieved from http://www.uasmagazine.com/articles/1601/ny-works-with-nasa-to-develop-uas-traffic-management-system

Yodice, J.S. (2015, August). The “see and avoid” rules: helping out the NTSB. Retrieved from https://www.aopa.org/news-and-media/all-news/2015/august/pilot/counsel

Zeitlin, A. D. (2010). Progress on requirements and standards for sense & avoid. MITRE Corporation. Retrieved from https://www.mitre.org/sites/default/files/pdf/10_2799.pdf