## 1 Introduction
While there is universal recognition that safety is paramount in this effort, many criticize that the FAA has been overly cautious due to a lack of policy differentiating drones and their abilities. Figure 1: (**A**) Impact of the Unmanned Aircraft Systems (UAS) industry © 2018, CTATM [5] (p. 4) and (**B**) Federal Aviation Administration (FAA) prediction of General Aviation (GA) UAS over 55 lbs. © 2018, CTATM [4] (p. 8). For example, current FAA policy treats a hobbyist drone the same as emergency services UAS [7] (p. 15). The balance between safety and growth has many stakeholders frustrated as technology leaps ahead, while the legal ability to utilize that technology lags behind. Every year that UAS integration into the NAS is unavailable, the US loses more than $10 billion amounting to $27.6 million per day of potential economic impact lost [8] (p. 2). In addition, stakeholders are calling for comprehensive legislature that would define responsibilities and liabilities in case of accidents so they may balance risk and reward and ensure that insurance and financial firms are able to support the UAS market because without safe protocols there will be no support for the market [9] (p. 3). UAS flight regulations, the scope of the issue, and the potential consequences cannot be taken lightly. In 2012, there were an estimated 200,000 h of domestic UAS operations and that figure was predicted to be at over a million hours in 2020 [10] (p. 17). In 2016, the FAA started a registration system to understand how many UAS there are in the US. Within the first month of opening the registration site there were nearly 300,000 UAS owners that registered their vehicles [3] (p. 2). In 2018 more than 175,000 new commercial UAS were registered, increasing the number in the US by more than 170% and expanding the total commercial market to 277,000 units. This far exceeded the 44% of growth that had been expected for the year [11] (p. 1). In the same report, the FAA predicted there would be around 452,000 commercial UAS in use by 2022, but that number was already reached by the beginning of March 2020 [12] (pp. 1 and 9). Based on the latest data the FAA now expects there to be 835,000 commercial UAS by 2023, which would mean a tripling of the market over five years [11] (p. 1). Experts also claim that 350,000 UAS pilots will be registered by 2023. As of May 2019, there were roughly 1.25 million amateur UAS in the US and that is expected to increase to 1.4 million by 2023 [11] (p. 2). Most recently, the FAA reports that as of 10 March 2020, a total of 1,563,263 UAS have been registered (441,709 commercial UAS and 1,117,900 recreational UAS) and 171,744 remote pilots have been certified [12] (p. 1). Furthermore, the FAA predicts that air traffic will continue to increase 1% per year for the next 21 years [13] (p. 27). FAA/NASA UAS Traffic Management Program: In response to the need for safely integrating UAS into the US National Airspace System, the FAA, in conjunction with NASA, implemented a joint program to manage this effort. The program, titled the UAS Traffic Management (UTM) system, was led via a FAA/NASA Research Transition Team (RTT). NASA took primary lead for the initial program with a series of flight campaigns focused on identifying and developing suitable technologies, tools, and procedures that would eventually allow Small UAS (sUAS) to operate safely within the NAS. The FAA focused on operationalizing the most promising technologies, tools, and procedures to develop more realistic planning scenarios and concepts of operation for implementation or further study. NASA UTM campaigns were named according to increasingly [14] (p. 1) complex Technical Capability Levels (TCLs) shown in Figure 2, moving from initial demonstrations of low-density UAS operations in sparsely populated rural areas (TCL1) and incrementally moving towards high-density, highly interactive scenarios requiring increased levels of UAS autonomy and system integration (TCL4).