Many applications of small Unmanned Aircraft System (sUAS) have been envisioned. These include surveillance of key assets such as pipelines, rail, or electric wires, deliveries, search and rescue, traffic monitoring, videography, and precision agriculture. These operations are likely to occur in the same airspace in presence of many static and dynamic constraints such as airports, and high wind areas. Therefore, small UAS, typically 55 pounds and below, operations need to be managed to ensure safety and efficiency of operations is maintained. This paper will describe the Concept of Operations (ConOps) for NASA's UAS Traffic Management (UTM) research initiative. The UTM ConOps is focused on safely enabling large-scale small UAS (sUAS) operations in low altitude airspace. The UTM construct supports large-scale visual line of sight and beyond visual line of sight operations. It is based on two primary mantras: (1) flexibility where possible and structure where necessary (2) a risk-based approach where geographical needs and use case indicate the airspace performance requirements. Preliminary stakeholder feedback and initial UTM tests conducted by NASA show promise of UTM to enable large-scale low altitude UAS operations safely.

https://ntrs.nasa.gov/api/citations/20190000370/downloads/20190000370.pdf

Unmanned Aircraft System Traffic Management (UTM) Concept of Operations

UAS Traffic Management (UTM) Concept of Operations to Safely Enable Low Altitude Flight Operations

Aviation technologies and concepts have reached a level of maturity that may soon enable an era of on-demand mobility (ODM) fueled by quiet, efficient, and largely automated air taxis. However, successfully bringing such a system to fruition will require introducing orders of magnitude more aircraft to a given airspace volume than can be accommodated by the traditional air traffic control system, among other important technical challenges. The airspace integration problem is further compounded by requirements to set aside appropriate ground infrastructure for take-off and landing areas and ensuring these new aircraft types and their operations do not burden traditional airspace users and air traffic control. This airspace integration challenge may be significantly reduced by extending the concepts and technologies developed to manage small unmanned aircraft systems (UAS) at low altitude - the UAS traffic management (UTM) system - to higher altitudes and new aircraft types, or by equipping ODM aircraft with advanced sensors, algorithms, and interfaces. The precedent of operational freedom inherent in visual flight rules and the technologies developed for large UAS and commercial aircraft automation will contribute to the evolution of an ODM system enabled by UTM. This paper describes the set of air traffic services, normally provided by the traditional air traffic system, that an ODM system would implement to achieve the high densities needed for ODM's economic viability. Finally, the paper proposes a framework for integrating, evaluating, and deploying low-, medium-, and high-density ODM concepts that build on each other to ensure operational and economic feasibility at every step.

/pdf/enabling-airspace-integration-for-high-density-on-demand-v1x9ddhbfj.pdf

Enabling Airspace Integration for High-Density On-Demand Mobility Operations

The operational goal of the ATD-1 ConOps is to enable aircraft, using their onboard FMS capabilities, to fly Optimized Profile Descents (OPDs) from cruise to the runway threshold at a high-density airport, at a high throughput rate, using primarily speed control to maintain in-trail separation and the arrival schedule. The three technologies in the ATD-1 ConOps achieve this by calculating a precise arrival schedule, using controller decision support tools to provide terminal controllers with speeds for aircraft to fly to meet times at a particular meter points, and onboard software providing flight crews with speeds for the aircraft to fly to achieve a particular spacing behind preceding aircraft.

https://ntrs.nasa.gov/api/citations/20120011953/downloads/20120011953.pdf

Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps)

This paper describes the implementation and evaluation of a trajectory prediction function. This function is a critical component of tactical flight management, a new concept that can increase the resiliency and robustness of trajectory based operations through a paradigm shift that improves Flight Management System (FMS) compatibility with tactical operations. The trajectory prediction function generates and continually updates the fourdimensional flight path that will be flown by the FMS. This motion-based trajectory represents an extension of the aircraft’s current state, and incorporates control laws, mode transition logic, and drag estimation as part of the prediction. The predicted trajectory is then displayed on navigation and vertical situation displays in an effort to reduce mode confusion occurrences and increase situational awareness of what the automation is doing now and what it will do in the future. These display features were evaluated in the Advanced Concepts Flight Simulator at NASA Ames Research Center to investigate the impact on flight crew energy state awareness when operating in the highly constrained and dynamic environment of the Next Generation Air Transportation System. Commercial airline crews flew multiple optimized profile descents under two conditions. In one condition, crews were presented with standard navigation displays, including a Vertical Situation Display (VSD). In the second condition, trajectory predictions were added to both the lateral map display and the VSD. Results show that predictive trajectory displays have the potential to improve situational awareness of the future automation mode and energy state of the aircraft, and that prediction accuracy and computational times are sufficient to support more advanced use in tactical flight management.

Implementation of a Trajectory Prediction Function for Trajectory Based Operations

In this paper, we describe NASA’s Air Traffic Management Demonstration-1 (ATD-1). The objective of ATD-1 is to operationally demonstrate the feasibility of fuel-efficient, high throughput arrival operations using ground-based and airborne NASA technologies for precision scheduling and spacing in conjunction with Automatic Dependent Surveillance Broadcast (ADS-B). ATD-1 integrates three research efforts that were conducted in the simulation laboratories at NASA’s Ames and Langley Research Centers in parallel for many years into the Interval Management-Terminal Area Precision Scheduling System (IM-TAPSS). IM-TAPSS will be further fine-tuned, verified and validated in laboratories and transitioned to a field prototype for an operational demonstration at a major US airport targeted for 2015. This paper describes the ATD-1 concept of operations, IM-TAPSS core components, research results to date, and the ATD-1 plans and status.

NASA's ATM Technology Demonstration-1: Transitioning Fuel Efficient High Throughput Arrival Operations from Simulation to Reality

NASA has developed an advanced arrival management capability for terminal controllers, known as Terminal Sequencing and Spacing (TSAS). TSAS increases use of performance-based navigation (PBN) arri...

https://ntrs.nasa.gov/api/citations/20190027237/downloads/20190027237.pdf

Enabling Performance-Based Navigation Arrivals: Development and Simulation Testing of the Terminal Sequencing and Spacing System

Interval Management is a suite of ADS-B-enabled applications that allows the air traffic controller to instruct a flight crew to achieve and maintain a desired spacing relative to another aircraft. The flight crew, assisted by automation, manages the speed of their aircraft to deliver more precise inter-aircraft spacing than is otherwise possible, which increases traffic throughput at the same or higher levels of safety. Interval Management has evolved from a long history of research and is now seen as a core NextGen capability. With avionics standards recently published, completion of an Investment Analysis Readiness Decision by the FAA, and multiple flight tests planned, Interval Management will soon be part of everyday use in the National Airspace System. Second generation, Advanced Interval Management capabilities are being planned to provide a wider range of operations and improved performance and benefits. This paper briefly reviews the evolution of Interval Management and describes current development and deployment plans. It also reviews concepts under development as the next generation of applications.

/pdf/interval-management-development-and-implementation-of-an-56597j9g19.pdf

Interval Management: Development and Implementation of an Airborne Spacing Concept

Interval Management Alternative Clearances (IMAC) was a human-in-the-loop simulation experiment conducted to explore the Air Traffic Management (ATM) Technology Demonstration (ATD-1) Concept of Operations (ConOps), which combines advanced arrival scheduling, controller decision support tools, and aircraft avionics to enable multiple time deconflicted, efficient arrival streams into a high-density terminal airspace. Interval Management (IM) is designed to support the ATD-1 concept by having an "Ownship" (IM-capable) aircraft achieve or maintain a specific time or distance behind a "Target" (preceding) aircraft. The IM software uses IM clearance information and the Ownship data (route of flight, current location, and wind) entered by the flight crew, and the Target aircraft's Automatic Dependent Surveillance-Broadcast state data, to calculate the airspeed necessary for the IM-equipped aircraft to achieve or maintain the assigned spacing goal.

William C. Johnson

Papers

Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps)

NASA's ATM Technology Demonstration-1: Transitioning Fuel Efficient High Throughput Arrival Operations from Simulation to Reality

Enabling Performance-Based Navigation Arrivals: Development and Simulation Testing of the Terminal Sequencing and Spacing System

Interval Management: Development and Implementation of an Airborne Spacing Concept

Human-in-the-Loop Assessment of Alternative Clearances in Interval Management Arrival Operations