Aircraft Edge Device Deflection for Emergency Descent

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Solution Overview

Problem

Conventional aircraft control systems are inadequate for achieving the required descent rate during emergency situations, such as rapid cabin decompression, as they often necessitate increased spoiler surface area or deflection, leading to sub-optimal wing configuration and potential aerodynamic/structural buffet.

Innovation Solution

An emergency descent system incorporating a flight control computer, edge control system, and speedbrake control device that automatically adjusts leading and trailing edge devices to maximize drag, allowing for increased descent rates without excessive weight or structural stress, by computing and implementing specific deflection angles for these devices in response to cabin pressure loss indications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If spoiler surface area or deflection is increased to achieve required descent rate, then descent rate is improved, but wing configuration becomes sub-optimal and aerodynamic/structural buffet occurs

Engineering Contradiction:
Improvedescent rateVSAvoidwing configuration stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The patent implements dynamic adjustment of leading edge and trailing edge device deflection angles based on real-time aircraft state (altitude, speed, angle of attack). The flight control computer continuously computes optimal deflection angles that maximize drag while maintaining stable wing configuration, replacing the static spoiler-only approach with a dynamic, multi-device control system that adapts to changing flight conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the deflection angle parameters of leading edge and trailing edge devices according to computed optimal values. By adjusting these angular parameters dynamically rather than using fixed spoiler deflections, the system achieves maximum drag for emergency descent while maintaining aerodynamic stability and avoiding buffet conditions.

Inventive Principle:
Principle #35Parameter changes

2Speed

If conventional control systems are used during emergency descent, then system complexity is minimized, but descent rate requirement cannot be met

Engineering Contradiction:
Improvedescent rateVSAvoidcontrol system complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent makes existing leading edge and trailing edge devices serve a dual function: their primary function for normal flight control and their secondary function for emergency descent by computing and implementing specific deflection angles that maximize drag. This multi-functionality allows the system to meet descent rate requirements without adding dedicated emergency descent hardware, thus limiting complexity increase.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The flight control computer automatically computes optimal deflection angles and commands the edge control system to adjust leading edge and trailing edge devices during emergency descent. This automated self-service control eliminates the need for manual pilot intervention and complex mechanical linkages, achieving high descent rates through intelligent software control of existing actuators.

Inventive Principle:
Principle #25Self-service

3Speed

If leading edge and trailing edge devices are automatically adjusted to maximize drag, then descent rate is improved, but control system complexity increases

Engineering Contradiction:
Improvedescent rateVSAvoidedge control system complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The flight control computer receives real-time feedback on aircraft state (altitude, speed, angle of attack) and continuously computes optimal deflection angles for leading edge and trailing edge devices. This closed-loop feedback control ensures the devices are positioned to maximize drag at each moment during emergency descent, achieving high descent rates through intelligent, adaptive control rather than simple mechanical systems.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively increases the aircraft's descent rate during emergency situations while maintaining optimal wing configuration, reducing the risk of buffet and improving safety by minimizing lift-to-drag ratio, thus meeting regulatory requirements.

Implementation Method 1

The flight control computer may be configured to compute a first setting for a leading edge device and/or a trailing edge device of an aircraft wing... automatically command the leading edge device, the trailing edge device, or both, to a deflection angle corresponding to the first setting... to maximize drag

Methodology Applied
Scientific EffectAerodynamic drag: Drag

Data Source

PatentEP2851289B1Leading and trailing edge device deflections during descent of an aircraft
Publication Date: 2018.05.09 THE BOEING CO
  • EP2851289B1 patent drawingFigure 1
  • EP2851289B1 patent drawingFigure 2
  • EP2851289B1 patent drawingFigure 3

AI summary

A system (300) for increasing the descent rate of an aircraft may include a flight control computer(450), an edge control system (460), and a speedbrake control device (532). The flight control computer may be configured to compute a first setting for a leading edge device (150) and/or a trailing edge device (240) of an aircraft wing. The edge control system may be communicatively coupled to the flight control computer and may include an edge control device (453) having a plurality of control device positions (458) including a cruise position (462). The speedbrake control device may include a plurality of speedbrake detents (536) including a flight detent (542). The edge control system (460) may be configured to automatically command the leading edge device (150), the trailing edge device (240), or both, to a deflection angle corresponding to the first setting if the edge control device is in the cruise position and the speedbrake control device is in the flight detent.