Can Unmanned Aerial Systems Integrate into the National Airspace System?

The Federal Aviation Administration’s (FAA) Next Generation Air Transportation System (NextGen) program seeks to increase efficiency, safety, and performance of the air traffic system within the United States.  The NextGen program centers around a combination of infrastructure, equipment, and procedural updates.  These upgrades include Automatic Dependent Surveillance-Broadcast (ADS-B), Collaborative Air Traffic Management Technologies, Data Communications, National Airspace System Voice System (NVS), NextGen Weather, and System Wide Information Management (SWIM) (FAA, Federal Aviation Administration, 2014).  A main capability these programs provide is the ability to share data among air traffic control centers, aircraft, airports, and commercial airline operations centers.  Increasing the data sharing amongst these agencies allows more precise decision making, enabling greater efficiency of air operations which can reduce emissions and produce savings for the operators as well as passengers.  This paper will address some of the NextGen programs that most directly relate to the introduction of unmanned aircraft systems (UAS) to the national airspace system (NAS).
The air transportation system is finally catching up with what vehicles on the ground have utilized for decades; the introduction of GPS to broadcast position, speed, and altitude.  The ADS-B Out portion of the system “uses GPS to determine an aircraft’s location, airspeed and other data. It broadcasts that information to a network of ground stations (which relays the data to air traffic controllers) and to nearby aircraft equipped to receive the data via ADS-B In” (FAA, NextGen Implementation Plan 2015, 2015).  The ADS-B In portion of the system “provides operators of properly equipped aircraft with weather and traffic information delivered directly to the cockpit” such as the Flight Information Service Broadcast (FIS-B) and the Traffic Information Service Broadcast (TIS-B) (2015).  This system will reduce the potential for human error when determining and broadcasting position, heading, and airspeed.  Pilots with ADS-B In terminals will have more accurate information available without the need for requesting data or transcribing it from the radio.  Mandatory equipage of ADS-B transponders begins in 2020, however, there is not a mandatory date for ADS-B equipage.  This will ensure all aircraft to feed the system while only those requiring the data must install ADS-B equipment. The ADS-B systems will require an increase in data communications on and off an aircraft.
We live in an increasingly data dependent world.  No longer is it acceptable to lose data capability during a flight.  NextGen Data Communications (Data Comm) closes that gap.  Data Comm enables “controllers and pilots to communicate with digitally-delivered messages” (FAA, NextGen Implementation Plan 2015, 2015).  Removing the necessity of radio voice communication will reduce miscommunications between air traffic controllers and aircraft.  The Data Comm implementation begins with predeparture clearances and route revisions.  Some realized benefits during initial stages of Data Comm rollout in Memphis and Newark included, “reduced communications time resulting in faster taxi outs, reduced delays and reduced pilot and controller workload” (2015).  With the increased implementation of the ADS-B system, Data Comm will become more important and will realize even greater benefits.
The evolution of the NAS transportation system brings with it an increased need for better, networkable communication across the country.  The NAS Voice System (NVS) answer this need.  Rather than the “current voice switches operated independently at individual facilities, NVS will use router-based communications linked through the FAA Telecommunications Infrastructure (FTI) network” (FAA, NextGen Implementation Plan 2015, 2015).  The new router based communication eliminates the obsolescence problem the current system is facing.  It will also allow “controller workload from one air route traffic control center to another as needed” (2015).  This flexibility will allow centers to adapt to surges caused by weather, maintenance, or unexpected outages.
Unmanned aircraft systems have, in effect, been using many of the features of NextGen in their operations already.  Ground control stations have been operating in a similar fashion to air traffic controllers when they are controlling multiple UAS.  This is a benefit NextGen can realize from UAS operations, the human factors of the unmanned systems.  The NextGen system relies increasingly on automation and data sharing to fulfill its goals.  Much of this relies upon the system resident on the aircraft such as ADS-B transceivers and Data Comm modules.  The addition of such equipment does not pose a large risk to manned aircraft from Cessna 152 sized aircraft up to jumbo airliners like the Boeing 787.  Unmanned aircraft in contrast are much more like satellite systems with strict constraints on size weight and power.  In addition, communications equipment associated with NextGen systems may create electromagnetic interference with the command, control, and data links used to operate the UAS.
Communication is key to successful aviation.  With manned aircraft, the pilot in command is resident in the aircraft itself.  Often large UAS such as Predators and Global Hawks are operated from a geographically separated facility.  This may require the UAS itself to act as a communications relay to transmit data from NextGen systems to the UAS then back to the command and control node.  This increases the data and communication latency.  This latency hinders the UAS pilots decision making ability as well as the response time once a decision is made.  In aviation, decision making and responses are time critical and can mean the difference in life and death.
The NextGen system was developed to address commercial and general aviation concerns in an increasingly congested NAS.  Unmanned systems were not a concern with the advent of NextGen.  For example, UAS flight hours increased nearly 6 times between 2005 and 2010 (Weatherington, 2010).  Since then, the types of UAS and quantity of flights has exploded.  The past six years has seen a boom in civil, consumer, and military UAS use.  Integration of UAS into the NAS will be a difficult task.
 
References
FAA. (2014, November 18). Federal Aviation Administration. Retrieved from NextGen Programs: http://www.faa.gov/nextgen/programs/
FAA. (2015). NextGen Implementation Plan 2015. Washington, DC: Office of NextGen.
Weatherington, D. (2010). Unmanned Aircraft Systems. OUSD (AT&L)/PSA.