Four-Dimensional Aircraft Guidance for Continuous Descent Approaches

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Solution Overview

Problem

Continuous descent approaches in aircraft are limited by reduced airport capacity due to the need for large spacing between aircraft to account for uncertainties in wind and piloting practices, which reduces the efficiency of air traffic control and increases noise pollution.

Innovation Solution

A method of guiding an aircraft to follow a predetermined four-dimensional flight path using elevator commands to correct along-track position deviations, allowing for more precise control and reduced thrust settings, thereby enabling closer aircraft spacing without compromising safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If continuous descent approaches are used to reduce noise and improve fuel efficiency, then noise pollution decreases and fuel consumption reduces, but airport capacity decreases due to reduced landing rates

Engineering Contradiction:
Improvenoise pollutionVSAvoidairport capacity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The system continuously monitors actual vertical and along-track positions and uses feedback control to generate thrust and elevator commands that correct deviations from the desired flight path, enabling precise four-dimensional trajectory tracking

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts thrust settings and elevator commands in real-time based on monitored position deviations, allowing the aircraft to adapt to wind changes and maintain precise trajectory control

Inventive Principle:
Principle #15Dynamics

2Reliability

If large spacing is imposed between aircraft to account for uncertainties in continuous descent approaches, then safety is maintained, but airport capacity is reduced

Engineering Contradiction:
ImprovesafetyVSAvoidairport capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Real-time feedback from position monitoring enables dynamic adjustment of separation requirements, allowing reduced spacing when trajectory control is precise while maintaining safety margins

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces tactical radar vectoring and manual corrections with automated four-dimensional guidance and control, providing more consistent and predictable trajectory following

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If conventional step-down approaches are used to maintain airport capacity, then landing rates are higher, but noise pollution increases and fuel efficiency decreases

Engineering Contradiction:
Improveairport capacityVSAvoidnoise pollution
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system enables dynamic thrust management during continuous descent, adjusting engine power to maintain optimal descent trajectory while minimizing noise and fuel consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The four-dimensional flight path is planned in detail before commencing the approach, pre-calculating the optimal trajectory that balances capacity, noise, and fuel efficiency requirements

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2423773B1Four-dimensional guidance of an aircraft
Publication Date: 2014.06.25 THE BOEING CO
  • EP2423773B1 patent drawingFigure 1
  • EP2423773B1 patent drawingFigure 2a~2b
  • EP2423773B1 patent drawingFigure 3

AI summary

The present invention relates to methods of controlling the flight path of an aircraft to follow as closely as possible a predetermined four-dimensional flight path, such as when flying continuous descent approaches. A method of controlling an aircraft to follow a predetermined four-dimensional flight path is provided that comprises monitoring an actual along-track position and an actual vertical position of the aircraft relative to corresponding desired positions on the predetermined flight path. Throttle commands and speed brake commands are generated based on deviations of the actual vertical position of the aircraft from the desired vertical position. Elevator commands are generated based on the deviation of the actual along-track position from the desired along-track position and on the deviation of the actual vertical position from the desired vertical position.