Flight-Path Angles

Flight-Path Angles (TOP2-255)
Optimum Strategies for Selecting Descent Flight-Path Angles
Efficient and safe arrival operations under challenging traffic conditions is a key objective for air transportation modernization efforts taking place throughout the world. However, trajectory predictability issues often prevent Air Traffic Control (ATC) from allowing continuous descent approaches in congested airspace. An arrival procedure with a specific descent profile such as a fixed-flight-path angle provides high trajectory predictability for air traffic management. Accordingly, it can enable ATC to increase the use of continuous descent approaches, thereby increasing the throughput of arrival operations and reducing fuel burn and other direct operating costs in the process. Moreover, such a procedure is already supported by current avionics in almost all small (regional, business, and light) jets and a fraction of large jets including Boeing and Airbus.

The Technology
This technology computes adaptable, fuel/cost-efficient, and flyable descent profiles for one or more aircraft for a particular airport, an arrival route, and a specific period of time. When used by ATC, it can aid the design of arrival procedures and assist the Efficient Descent Advisor (EDA) to realize its full benefits in guiding arrival flights through the transition airspace. When used by airlines, it can potentially reduce the direct operating costs of their arrival flights, particularly for those flying to outstation airports. The algorithms select a descent profile, characterized by a flight-path angle or a descent rate, for one or a group of arrival flights. The minimum-fuel strategy achieves the most fuel benefit but requires communication of the profile in real time (e.g., via data link or voice communication). The other two strategies are less efficient but simpler to implement, and can be used to define more efficient arrival procedures. The algorithm compares fuel and flyability of each trajectory and selects a profile based on aggregated fuel benefits. Three strategies for selecting the descent profile are proposed. The minimum fuel strategy achieves the most fuel benefit but requires communication of the profile in real time such as data link or voice communication. The other two strategies are less efficient but simpler, and can be used in defining an arrival procedure.
Vertical profile of descent flight-path angles
  • Computes the most fuel-efficient/flyable descent profiles for one or more aircraft
  • Adapts parameters for prevailing winds, a particular airport, directions and/or routes during a specific time frame
  • Improves throughput in the transition airspace
  • Reduces operating costs for airlines

  • Federal Aviation Administration
  • Airline operations
Technology Details

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