Primary Flight Display Sky Veil for Brown-Over-Brown Awareness

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Solution Overview

Problem

Brown-over-brown display conditions on avionic primary flight displays can cause confusion and disorientation for pilots, as they obscure the sky's position relative to terrain, compromising situational awareness.

Innovation Solution

An avionic display system that renders a partially transparent sky veil on the primary flight display, allowing terrain to be visible through transparent portions of the sky veil, which maintains the sky's position indication regardless of the aircraft's attitude.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sky veil is rendered on the primary flight display to indicate sky position, then situational awareness is improved, but the display complexity increases

Engineering Contradiction:
Improvesituational awarenessVSAvoiddisplay complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sky veil is segmented into multiple horizontal bands with different transparency levels. The upper portion has higher transparency to show terrain, while the lower portion has lower transparency to indicate sky position. This segmentation allows the system to provide both terrain visibility and sky position indication without requiring a completely opaque veil, thus reducing the increase in display complexity while maintaining situational awareness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the sky veil are assigned different transparency properties. The upper region is more transparent to allow terrain viewing, while the lower region is less transparent to clearly indicate sky position. This local differentiation of transparency creates a functional gradient that addresses multiple display requirements simultaneously, improving situational awareness without uniformly increasing display complexity across the entire screen.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the sky veil is made transparent to show terrain, then terrain visibility is improved, but the sky position indication becomes less clear

Engineering Contradiction:
Improveterrain visibilityVSAvoidsky position indication
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The sky veil is divided into horizontal segments with varying transparency. Upper segments are more transparent for terrain visibility, while lower segments are less transparent for clear sky position indication. This segmentation allows both requirements to be satisfied simultaneously in different regions of the display.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sky veil employs local quality differentiation where transparency varies by vertical position. The lower portion maintains lower transparency to preserve sky position information, while the upper portion increases transparency to enhance terrain visibility. This localized property change ensures that neither terrain visibility nor sky position indication is compromised.

Inventive Principle:
Principle #3Local quality

3Loss of information

If the sky veil extends further down to indicate sky position, then sky position indication is improved, but the terrain visibility through the veil is reduced

Engineering Contradiction:
Improvesky position indicationVSAvoidterrain visibility
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The sky veil is segmented into multiple transparency zones rather than being uniformly opaque or transparent. This allows the veil to extend vertically to indicate sky position while maintaining transparent portions that allow terrain viewing. The segmented structure prevents complete occlusion of terrain while still providing adequate sky position information.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different vertical regions of the sky veil have different transparency qualities. The lower regions extend further to indicate sky position but maintain sufficient transparency to allow terrain visibility. This local quality variation enables the sky veil to serve dual purposes: indicating sky position and maintaining terrain visibility, thereby resolving the contradiction between the two requirements.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4449060B1Rendering a sky veil on an avionic primary flight display
Publication Date: 2026.01.21 LEONARDO SPA
  • EP4449060B1 patent drawingFigure 1
  • EP4449060B1 patent drawingFigure 2
  • EP4449060B1 patent drawingFigure 3

AI summary

An avionic display software for an aircraft (2) comprising: a display device (3) coupled to receive image rendering display commands and responsively display rendered images; a terrain data source (4) to output terrain data representative of terrain in a field of view of a pilot (13) of the aircraft (2); an avionic flight data source (10) to output avionic data representative of an avionic state of the aircraft (2), including a roll angle thereof; and computing resources (6) coupled to the terrain data source (4) to receive terrain data therefrom, to the avionic flight data source (10) to receive avionic data therefrom, and to the display device (3) to supply image rendering display commands thereto based on the received terrain and avionic data. The avionic display software is executable by the computing resources (6) to cause, when executed, the computing resources (6) to become programmed to cause rendered images representative of an out-the-window view of the operator of the aircraft (2) to be displayed by the display device (3). A rendered image comprises one or both of rendered terrain (RT) and rendered sky (RS), which are representative of real-world terrain and sky outside of the aircraft (2) and whose positions and orientations are dependent upon position and orientation of the aircraft (2) relative thereto. A rendered image further comprises a rendered sky veil (SV). The sky veil (SV) is an overlapping graphic representation rendered at least partially transparent in such a manner that (i) portions of the rendered sky veil (SV) that (eventually) overlap with the rendered sky (RS) are not discernable from the rendered sky (RS), and (ii) the rendered terrain (RT) is viewable through transparent portions of the sky veil (SV) that overlap with the rendered terrain (RT). The sky veil (SV) is rendered as a band stationary in the rendered image during roll of the aircraft (2). The sky veil (SV) is rendered at least partially transparent along its width (W) such that a width (WR, WL) of a transparent region of the sky veil (SV) depends on a roll angle of the aircraft (2).