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Unmanned Cargo Aircraft is the Way of The Future for Air Delivery






Unmanned Cargo Aircraft is the Way of The Future for Air Delivery
Raymond J. DeMarco
Embry Riddle Aeronautical University Worldwide


Abstract
A good argument can be made that unmanned cargo aircraft save the air cargo industry billions of dollars while filling a gap in the cargo shipping industry.  When Federal Aviation Administration (FAA) regulations permit large unmanned aircraft to fly in the national airspace system (NAS), shipping companies will seek a new way of delivering materials through the air.  A great advantage for Unmanned Cargo Aircraft (UCA) design is cost efficiency due to reduced fuel consumption and lesser crew cost. Safety of property and people are of greatest concern along with information, command and control security.  ADS-B is a major contributor to sense and avoid technology requirements to allow manned and unmanned aircraft to work in unison and maintain separation.  Avoidance will play a major role for safety and ultimately the existence of Unmanned Cargo Aircraft (UCA).  This case analysis evaluates the advantage of unmanned aerial freight transport to sea and current aerial cargo transport.  Security, avionics and flight management systems shall satisfy FAA standards for airworthiness of the UCA.  This paper addresses the significance of issues of technical and safety challenges on the unmanned cargo market.








Summary
            Up to the hour, the world of unmanned aerospace is constantly evolving.  Automation in aviation reduces reliance of the human operator where the use of computer autonomy can increase efficiency and reliability.  The field of unmanned and Remotely Piloted aircraft (RPA) is expanding rapidly; there are a multitude of different roles an Unmanned Aircraft System can fill such as wildfire monitoring, industrial logistics, agriculture, firefighting and many more, some of which can only be done by a UAV.  Within a matter of time, unmanned aircraft technologies and airspace authorization of commercial unmanned flight will push the commercial sector to match that of unmanned military flight.  There are great challenges ahead before routine flight of heavy unmanned aircraft in non-segregated airspace is possible.  What does it take to put a heavy UAV cargo aircraft in the National Airspace System (NAS)?
            Unmanned aircraft for civil use has become evident and beginning to be taken more seriously for commercial use.  Safety of flight is major concern with unmanned aircraft operating routinely in non-segregated civil airspace.  From an air traffic perspective unmanned aircraft must appear and behave no differently than a Conventionally Piloted Aircraft (CPA).  Personnel should acquire the appropriate licensing, and the Unmanned Aerial Vehicle (UAV) must meet the airworthiness standards.
            One of the greatest concerns for FAA integrating UAVs into the NAS is safety and Sense and Avoid (SAA) technology.  “The FAA has mandated that aircraft operating in most controlled U.S. airspace be equipped for ADS-B Out by January 1, 2020 (NextGen – ADS-B, 2017).”  This technology that can be shared with manned and unmanned aircraft will be a significant step for SAA capability and permission for UAV flight in non-segregated airspace.  Security of flight for UAVs goes hand-in-hand with safety.  Protection from hacking command and control as well as information security is of major concern.  There is bright future ahead as UAVs become larger and more functional.
Issue Statement
            A platform for unmanned cargo aircraft that is designed specifically for cargo delivery nationally and worldwide will become an inevitable demand when freight can be transported at a lesser cost than by manned aircraft and faster than sea cargo filling a middle gap.  Production and integration of UCA within the NAS will open new markets for transportation of material goods dependent upon Federal Aviation Administration (FAA) and International Civil Aviation Organization (ICAO) regulations.
Significance of the Issue
            In 2009 FedEx founder Fred Smith had a conception that its aerial cargo service would soon shift to Remotely Piloted Aircraft Systems (RPAS) once the FAA regulations allowed integration of FedEx aircraft into the National Airspace System (Butterworth-Hayes, 2013).  Smith had an idea of blended wing cargo aircraft that would have a greater carrying capacity than the current FedEx fleet, and would also lower freight prices.  In February of 2012 President Barack Obama unveiled a deadline for U.S. regulators to create full integration of UAS (Unmanned Aircraft Systems) into U.S. airspace by the end of 2015.  With the slower than anticipated progress of airworthiness regulations for integration of UAS in national airspace, the dream of UCA zipping through the skies has also slowed progress. 
Demand
The air freighter industry is here to stay.  As of 2015, Boeing currently has 1,770 freighters in service and plans to have 3,010 by the year 2035 (Boeing: Freighters, 2017).  The U.S. experienced an increase of 13% in air freight from March 2016 to March 2017 between the U.S. and the rest of the world during that period (US DOT, 2017).  As of March 2017, the Middle East air freight shipments to and from the U.S. rose 17% from the preceding 12-month period while Canada experienced a 11% increase (US DOT, 2017).  Since the recession there has been growth in the air freighter industry.  When UAVs can fly internationally in non-segregated airspace, for a lesser cost than manned aircraft the demand for UCA across the globe may grow significantly.
Economic Effects
            By missing the 2015 deadline, Gretchen West, the executive vice president with the Association for Unmanned Vehicle Systems International stated that the delay for integrating UAVs into the NAS will cost the U.S. $10 billion per year.  UCA may not necessarily compete with existing aerial transport, but may open new markets to areas throughout the world that may not have a feasible ground infrastructure or where there is a lack of demand for expensive air freight.  The size of the market is unknown but for intercontinental delivery of material goods, there is reason to believe there will be a great enough demand for a less expensive method for UCA that this market can prove to be worth the development (The Platform for Unmanned Cargo Aircraft (PUCA), 2017). 
FAA Regulation Issues         
            Unmanned aircraft creators are chomping at the bit to get access to U.S. airspace.  Currently commercial UAV access to airspace is limited with permission by a Certificate of Authorization (COA) to operate with Direct Line of Sight (DLOS) under specific conditions agreed upon by the FAA and the UAV operators.  Safety is a leading concern while the ability to for UAVs to Detect and Avoid (DAA) and maintain separation autonomously is a leading factor.  The FAA has called “for a target level of safety that is more stringent than the see-and avoid requirement for manned aircraft (Wikle, 2017).”  Engineers design algorithms for collision detection and collision avoidance.  The self-separation algorithms identify potential intruders and “plan new paths that remain well clear of intruder aircraft (Wikle, 2017).”
Avionics, Navigation and Security
There are information and navigation security challenges between a Ground Control Station (GCS) and the UCA such as loss of link, data transfer rates, and working beyond a direct line of sight.   Secure communication link between the ground control station (GCS) and the aircraft, embedded with encryption and decryption add complexity and cost but are imperative for safe operation of a UAV (Howard, 2017).  Secure communication is necessary, so the UAV cannot be hijacked.  In civil airspace, robustness of UAV software code is paramount to minimize vulnerability.  With safety as chief concern, a UAV can only be considered safe if it cannot be controlled by a hostile intruder.
Human Factors
            Human pilots in the cockpit bring certain limitations to flight.  Removing a human from the cockpit for an autonomous aircraft may eventually eliminate human pilot error such as misinterpreting information, lapse in judgement, and other mistakes.  Physiological limitations such as fatigue due to long flight times, jet lag, and need for environmental systems such as oxygen and cabin pressurization will remain factors for manned flight.  Pilots must adhere to duty and rest cycles according to 14 CFR 91.1059 as shown in figure 1.  The limitations for human pilots requires major planning for qualified pilots, scheduling and adhering to the rest cycles.  Pilots must rest 14-18 hours after multi time-zone flight and are limited to 10-12 hours of duty with a maximum of 14-hour duty day ("eCFR — Code of Federal Regulations", 2017).  The need to get pilots to destinations in a timely manner requires flight at a higher speed that is considerably less fuel efficient; an UCA will fly at a much more fuel-efficient speed (See
Figure 1:  Flight time limitations for pilots per Code of Federal Regulations ("14 CFR 91.1059 - Flight time limitations and rest requirements: One or two pilot crews.", 2017)
alternative actions).
Alternative Actions
Avionics, Navigation and Security
Encompassed in aircraft safety of flight is security, avionics and navigation systems.  This is a major piece of the issue for UAS integration in national airspace.  For safe flight of UCA, the aircraft needs to know where it is, where it wants to go and where other aircraft and hazards are.  Algorithms are the basis of an artificial intelligence to use the information at hand to make decisions to sense and avoid, and prevent incursion.  For UCA to take form, unmanned flight needs to operate seamlessly in all airspace.
IT.  Information Technology (IT) security common criteria must be applied to UAV communications.  ISO 14508 is an international process-oriented standard that defines IT security requirements with 7 Evaluations Testing Assurance Levels (EALs).  These requirements include audit, communications, cryptography, data protection, authentication, security management, and privacy (Pitchford, 2017). These principles should be applied to UAV communications.  The 2011 crash of the CIA UAV in which the GPS was hacked and diverted the vehicle.  This case underlines the vulnerabilities and necessity for a robust information security system.  An UCA carrying valuable material goods cannot afford to be hijacked.
Robust software validation and verification processes for aviation currently are defined by DO-178.  Traceability, software design and coding ensure confidence in and the correctness and control of avionics software (Pitchford, 2017).   Aircraft must pass avionics airworthiness authorization by the FAA; DO-178B is recognized as the standard for the certification of the software portion of an avionics system (Jain, 2013). It must be noted that DO-178 and ISO 14508 standards for aviation are not required for UAVs.  These are the current standards for manned aircraft.  The scenario for a large unmanned aircraft is understandably different; we should see that FAA standards for avionics software for UAVs may differ regarding the fact that command and control is not generated within the aircraft, but by digital transmission. 
            Aircraft Separation.  Each development brings UAS closer to their consent in the NAS.  NASA conducts collaborative research “with the Federal Aviation Administration (FAA), the Radio Technical Commission for Aeronautics (RTCA) and commercial aerospace entities to develop minimal operation performance standards (Behar, 2017).”  For UASs, detecting is to determine there is an object in the airspace but not to assume the object has been identified.  Sensing is to determine that the object is or is not a threat to a UAS.  Avoidance is to initiate movement from the flight path to a new heading and back to the original course.  Automatic Dependence Surveillance Broadcast (ADS-B): a technique that is ideal for SAA application on a sUAS.
ADS-B Application.  Sense-and-avoid (SAA) capability is a key enabler for UAS to safely have access to all ranges of airspace.  The approach to automatic detection should be a unified method for air-based and ground-based SAA.  For manned aircraft TCAS and ADS-B is a cooperative sensor solution and warn aircrew of air traffic.  Due to constraints for size and weight, TCAS cannot be applied directly to smaller UAVs and has demonstrated it is not ideal for use at airports and other dense airspace conditions (Zhao, 2016). 
Figure 2: ADS-B architecture (Zhao, 2016)
A long-term solution for SAA is real-time ADS-B data.  Through experiment, algorithms designed with ADS-B data can generate capability to effectively sense and avoid intruders.  “ADS-B can obtain the position, speed, course and other information of the host aircraft via the integrated Global Position System (GPS) and send it out in the form of broadcast, while the aircraft or ground control station can receive the precise location data broadcast information which equipped with the same ADS-B (Zhao, 2016).”  
ADS-B satellite traffic management is effective, economical and will optimize the cohesion of UAS and manned aircraft.  ADS-B technology is a satellite air traffic control (ATC) system and will eventually phase out ATC radar.  Not only is the cost of an ADS-B ground station one-ninth of the conventional ATC secondary radar, its data monitor updates faster at every second (Zhao, 2016).  ADS-B is also used for ground movement and helps prevent runway incursion.  GPS sensors support a 2-way system function.  “ADS-B OUT transmits aircraft flight number, address code, heading, speed, vertical speed (Zhao, 2016)” and other information such as weather and route reflection.  ADS-B IN receives ADS-B OUT data that other aircraft have broadcasted.  The architecture is shown in figure 2.  The onboard processer is provided real-time information of the airspace environment, and increases situational awareness for the autonomous UCA. 
While ADS-B is not an obstacle avoidance system, it is a crucial technology to be shared by manned and unmanned aircraft; it will prove to be a tool moving forward for the integration of UAS in all airspace.
Human Factors
            With the human factor removed of fatigue from long duration flights, aircraft can fly slower at a higher fuel efficiency.  For example, the optimal speed for fuel consumption for a certain aircraft would be too lengthy impractical for a slow long-distance flight due to crew fatigue.  In 2008 JetBlue added an average of 2 minutes to each flight saving $13.6 million while Northwest Airlines added four minutes to its flights to and from Hawaii saving $600,000 a year on Hawaii flights alone (Wilen, 2008).  Passengers would like to get their destinations as soon as possible while cargo is more patient.  If JetBlue saved $13.6 million in 2008, how much could FedEx and other air freight companies save flying 100 miles per hour slower?  Aircraft made to carry cargo at a slower speed without human pilots on board may yield substantial savings and attract more customers as a result.
            Situation awareness at the Human Machine Interface (HMI).  An Unmanned Aircraft System (UAS) operator’s ability to sense, feel, and react is unlike a manned aircraft.  Through egocentric teleoperation, the operator relies on the HMI to supply the information about the environment that must be accurately perceived and comprehended to safely and effectively perform the task of the mission.  The level of autonomy and the people accountable for the operation of the system share the responsibility of SA.  “As the level of unmanned vehicle system autonomy varies, the unmanned vehicles and humans will contribute to one another’s situation awareness (Freedman, 2007).”  With a pilot deprived of direct sensory information, the rich sensory information of the environment and state of the vehicle is not directly available (Endsley, 2013).  The crew in charge of the operation has no more than the information at hand to make the decisions where timing and precision is important.  Inserting UAVs into the National Airspace System, such as an UCA, the ground control station the operators may be commanding multiple aircraft simultaneously.  There is a still a cost for personnel to manage the flight of unmanned aircraft, but swapping out the pilot is as simple as a good turnover report instead of hotel and travel costs.
Recommendations
            Autonomous cargo aircraft will need a starting point.  Rather than fly over populated land areas, their ports should be placed at coastlines.  For the industry to get off the ground it may need to fly missions across the ocean.  Natilus Inc. plans to fly a 140-foot UAV with 200,000 pounds from Los Angeles to Hawaii in 2019 (Freeman, 2017).  Natilus has a vision for the future of international cargo transport.  Natilus believes it can carry approximately 200,000 pounds of cargo, like a 777, at half the cost due to fuel efficiency and lesser cost for crew.  Air cargo is high speed and high cost while ocean freight is slower and less expensive.  UCA would grant a middle price for middle transit times.
            Radio communication in the air between UAVs and ATC is one-sided.  As some military aircraft pilot are familiar with, the Northrop Grumman Global Hawk speaks on the radio with ATC and its communication is directive.  All other aircraft in the vicinity will yield to the Global Hawk on its flight path to avoid and possible incursion.  The Global Hawk is the first aircraft to be NAS certified (Northrop Grumman Newsroom, 2003).  Although this is not a practical solution when airspace becomes occupied with UAVs, manned aircraft giving way to UAVs may be a starting point for UCA in controlled airspace.
            ADS-B can be shared with manned and unmanned aircraft.  This should be used as a major connection for their coexistence.  ADS-B is one of the foundations of NextGen as its coverage area is greater than radar and transmits surveillance information of aircraft in flight or on the ground (faa.gov, 2017).  “The FAA has mandated that aircraft operating in most controlled U.S. airspace be equipped for ADS-B Out by January 1, 2020 (faa.gov, 2017).”    Unmanned aircraft operators receive traffic and weather information; this brings the remote operator closer to the realism of being on board providing greater situational awareness.
            Since most commercial flight is over 20,000 feet altitude, what are the possibilities that there can be designated UAV airspace for commercial use?  Manned aircraft will not enter this space therefor it will be unlikely that a near miss or collision would occur.  ADS-B out shall be a minimum requirement for example on a crop monitoring UAV.  This can apply to Natilus’ idea of international flight; crossing the ocean at 8000 feet, this low altitude space over the pacific ocean can be designated for UAVs.


References

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