Trajectory-based operations (TBO) are accomplished through 4D trajectories. A 4D trajectory is computed by automation (ground and/or flight deck) and defines the flight path of an aircraft from one point to another in four dimensions latitude, longitude, altitude, and time.

Trajectory-based operations have three key components:

The challenges of implementing TBO include:

NASA has been developing trajectory-based systems to improve the efficiency of the National Airspace System during specific phases of flight and is now also exploring Advanced 4-Dimensional Trajectory (4DT) operational concepts that will integrate these technologies and incorporate new technology where needed to create both automation and procedures to support gate-to-gate TBO. A TBO Prototype simulation toolkit has been developed that demonstrates initial functionality that may reside in an Advanced 4DT TBO concept. In September 2016, controller and pilot subject matter experts (SMEs) were brought to the Air Traffic Operations Laboratory at NASA Langley Research Center for discussions on an Advanced 4DT operational concept and were provided an interactive demonstration of the TBO Prototype using four example en route scenarios. The SMEs provided feedback on potential operational, technological, and procedural opportunities and concerns. After viewing the interactive demonstration scenarios, the SMEs indicated that the operational capabilities demonstrated would be useful for performing TBO while maintaining situation awareness and low mental workload. The TBO concept demonstrated produced defined routings around weather which resulted in a more organized, consistent flow of traffic where it was clear to both the controller and pilot what route the aircraft was to follow. In general, the controller SMEs reported that traffic flow management should be responsible for generating and negotiating the operational constraints demonstrated, in cooperation with the Air Traffic Control System Command Center, while air traffic control should be responsible for the implementation of those constraints. The SMEs also indicated that digital data communications would be very beneficial for TBO operations and would result in less workload due to reduced communications, would eliminate issues due to language barriers and frequency problems, and would make receiving, loading, accepting, and executing clearances easier, less ambiguous, and more expeditious. The feedback obtained during this activity will be used in future research and development of Advanced TBO concepts.


High-Fidelity Aircraft Simulation (top) Communicating with TBO-TIGAR (bottom) in a Laboratory Environment

High-Fidelity Aircraft Simulation (top) Communicating with TBO-TIGAR (bottom) in a Laboratory Environment

TBO-TIGAR is a capability developed to prototype, demonstrate, and assess the impact of proposed functionality for TBO. NASA is developing concepts and technologies that fundamentally change how air traffic is managed in a future TBO airspace system. TBO-TIGAR allows researchers to quickly prototype certain elements of these concepts and technologies in a low-fidelity environment, demonstrate them to various air traffic management and operations stakeholders, and obtain first-order measurements of their benefits or impacts to the overall air traffic system. These rapid prototyping activities are fundamental to the early refinement of these concepts and technologies. Functionality that is prototyped within TBO-TIGAR and exhibits potential benefits to the air traffic system can then be further analyzed in higher fidelity simulations or operational system, where the time and resources required to implement such functionality is much greater than with TBO-TIGAR.

The capabilities of TBO-TIGAR include:

High-Level Goals

The Rapid Research Design and Development (R2D2) platform allows researchers to test and demonstrate TBO concepts, tools, and enabling technologies in-situ using emulations and simulations of avionics and communication infrastructures, thus obviating the need for commercial off-the-shelf hardware and eschewing the costs of these systems. The R2D2 platform contains several components: research displays and interfaces, pilot displays and interfaces, DataComm Surrogate, and Spider tool.

Emulated Flight Displays

The R2D2 Platform is currently designed to be read-only from the aircraft, i.e., no data generated by the R2D2 platform is supplied directly to the research vehicle. For this set of operational trials, it is the responsibility of the human operator (the pilot at the researcher’s command) to follow guidance generated by the R2D2 platform and provide manual inputs into the aircraft’s flight systems such as the Mode Control Panel (MCP) or Flight Management System (FMS). Figure 3 (R2D2_SysArch.png) illustrates the system architecture for the R2D2 platform.

The R2D2 platform was successfully tested in October of 2016 and demonstrated the capability to test flight-deck based TBO concepts. Future work includes integrating this platform with the TBO-TIGAR suite, building new TBO tools into the platform, and accommodating and testing new communication technologies.

Tech POC: Bryan Barmore