UAS Integration into Civil Airspace. Douglas M. Marshall

Preface

      In early 2009 Fred Smith, founder, chairman and CEO of the venerable cargo airline, FedEx, declared in an interview that he would like to switch the FedEx fleet to unmanned aircraft as soon as possible, but would have to wait for the FAA to sort out the rules for national airspace integration. In his view, unmanned cargo freighters offer many advantages for his company, predicting that they would be safer, cheaper, and would boast a greater capacity. The result would be a reduction of airfreight prices from ten times the cost of surface-carried freight to a factor of two, with all the speed advantages of air over ground or ocean transportation. Smith pointed out that the modern version of the Boeing 777 is already capable of being operated unmanned, in that the aircraft can take off, fly, navigate, and land without human intervention (and could even be equipped with an autonomous ground guidance system so the aircraft can be “driven” around an airport environment without running into or over someone or something). The same is true of most of the newest passenger aircraft types. The cost savings would derive from the fact that even a single-pilot aircraft requires a completely different design, with radically different economics and logistics. Smith might characterize the economic opportunity as “unused capacity,” or what can be removed from the airplane that would allow an increased load. Systems such as oxygen, pressurization system, lavatories, extra seats, gallies, all intended for the comfort of the crew, can be eliminated and replaced with revenue-generating non-breathing cargo. The concept is not a pipe dream. Northrop Grumman’s Global Hawk reconnaissance aircraft, which is the size of a small business jet, has been flying entirely autonomous missions for several years, meaning that the aircraft is capable of taxing to the runway, taking off, executing its flight plan, and landing at its intended destination without any human intervention.

Aside from the obvious concerns from those who do not trust technology to safely permit a large commercial aircraft to operate without a pilot on board, even over the oceans rather than populated terrain, Smith hit on one of the key elements that inhibits such operations from being approved by government regulators. The “holy grail” in the small UAS technology space is now national airspace (NAS) integration. Will society ever get to the point where autonomous systems will be allowed to operate in the same airspace as manned or piloted aircraft, or even be sufficiently comfortable with the safety mitigations to travel in an aircraft without a pilot on board? While the concept is no longer in the realm of futuristic representations of how things will be in 2050, as depicted in motion pictures and television productions, scaled-down versions of that vision are in the making now. Electrically powered aircraft are in the airworthiness approval stage with the FAA. Urban air mobility concepts under development by companies such as Airbus, Joby Aviation, Kitty Hawk, Lilium, Terrafugia, and Uber Air are well on their way to securing civil aviation authority approvals to market eVTOL (electric vertical takeoff and landing) prototypes that can operate at low altitudes in urban environments. “Self-flying” air taxis are already taking passengers on test flights in Chinese cities. Researchers, developers, regulators, and others are working very hard to create remotely piloted systems that can share airspace at lower airspace levels, in an environment that is unlikely to confront a remotely piloted B777 loaded to the rafters with computer chips and smart phones, and flying at 400 feet above ground at 250 kts. What is now possible is a remotely or autonomously piloted aircraft carrying emergency medical supplies to a person in need, dispatched from the nearest public safety facility and operating in your neighborhood at an altitude of less than 250 feet above ground level (AGL), possibly saving a life. Or delivering that FedEx package that may have been carried to a distribution center by a conventional aircraft, but replacing the ground vehicle currently needed to complete the last leg of the journey. While technologically possible now, these scenarios may only take place outside of strictly controlled test environments under the watchful eyes of regulatory agencies such as the US Federal Aviation Administration or its functional equivalents elsewhere, national civil aviation authorities.

      There are many moving parts in the realm of unmanned aircraft systems. Capturing all of them and doing them justice would require several volumes. The one essential component of the UAS “big picture” is airspace management; thus the focus of this book. Even that subcategory calls for a recursive analysis, as any technology is made up of many components that themselves are technologies, which have subparts that are also technologies, and so on, in a repeating, or recurring fashion. The airspace management function is typically the exclusive province of civil aviation authorities focused on safety and the fundamental goal of keeping aircraft separated from one another so as to not create a hazard of a mid-air collision. This function has been largely successful for over 60 years, depending upon the country in question. Generally, the denser the airspace traffic, the greater the likelihood of a mishap. Midair collisions, though relatively rare when compared to the number of aircraft in flight at any one time in congested airspace, such as parts of the US and Europe, still happen, often with tragic results. In the list of the top 10 leading causes of fatal general aviation accidents in the US from 2001 to 2017, the last year this statistic is available, midair collisions ranked number eight. The number of near-midair collisions reported each year is approximately 200, and actual collisions average between 15 and 20. General aviation hours flown (those most important to our analysis because they are more likely to be found at low operating levels), totaled 25.9 million in the calendar year 2019.

The theme of this book focuses on just one of those many moving parts, the integration of unmanned aircraft into controlled and uncontrolled airspace. The ongoing regulatory and policy efforts around the world to achieve full