Embedded Lightning Arrester Structure for Stealth Aircraft

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Solution Overview

Problem

Lightning protection for low observable vehicles, such as stealth aircraft, poses a challenge as existing solutions either fail to provide adequate protection or increase the radar backscatter cross section, leading to potential damage from lightning-induced thermomechanical stress.

Innovation Solution

A lightning arrester comprising a support structure made from a high thermal stability metal alloy, such as tungsten, and a diverting structure with high electrical conductivity, like copper, which is embedded within the support structure to prevent melting or vaporization during a lightning strike, thereby maintaining radar transparency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large metallic structure is used to divert lightning current, then lightning protection reliability is improved, but radar backscatter cross section increases

Engineering Contradiction:

Improvelightning protection reliabilityVSAvoidradar backscatter cross section

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a composite structure consisting of a metallic diverting element embedded in a radar-absorbing material matrix. The metallic component (e.g., copper or aluminum) provides high electrical conductivity for lightning current diversion, while the surrounding radar-absorbing material (e.g., carbon-loaded epoxy or ferrite composite) absorbs electromagnetic waves and prevents radar reflection. This composite approach allows simultaneous achievement of reliable lightning protection and low radar signature.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The metallic diverting element is strategically positioned only at the leading edges and other high-risk lightning strike zones of the aircraft, rather than covering the entire surface. The size, shape, and distribution of these metallic elements are optimized to provide adequate lightning protection only where needed, minimizing their radar cross section contribution while maintaining protection reliability in critical areas.

Inventive Principle:

Principle #3Local quality

2Reliability

If metallic structures are applied on RAS surface, then lightning diversion capability is improved, but radar transparency deteriorates

Engineering Contradiction:

Improvelightning diversion capabilityVSAvoidradar transparency

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The metallic diverting element is nested within or embedded in the radar-absorbing structure. The metallic component is positioned inside a cavity or channel formed in the radar-absorbing material, or partially embedded in it. This nesting arrangement allows the metallic element to perform its lightning diversion function while being shielded by the radar-absorbing material, which prevents the metallic surface from directly reflecting radar waves.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Object-affected harmful factors

If segmented diversion strips are used, then radar transparency is maintained, but lightning protection reliability is reduced due to surface contaminants

Engineering Contradiction:

Improveradar transparencyVSAvoidlightning protection reliability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent employs a continuous metallic diverting element with a streamlined, aerodynamic shape that is smoothly integrated into the aircraft surface. This continuous structure eliminates the gaps and joints present in segmented diversion strips, preventing accumulation of surface contaminants, water films, and ice deposits. The smooth, continuous metallic surface maintains reliable electrical conductivity for lightning current diversion while being seamlessly embedded in or covered by radar-absorbing material to maintain radar transparency.

Inventive Principle:

Principle #30Flexible shells and thin films

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 proposed solution effectively provides reliable lightning protection for low observable vehicles without significantly increasing the radar backscatter cross section, and it is resistant to surface contaminants and environmental conditions like ice deposits, reducing maintenance needs.

Implementation Method 1

a support structure made from a high thermal stability metal alloy, such as tungsten

Methodology Applied

Scientific EffectThermal stability: Refractory Material

Implementation Method 2

a diverting structure with high electrical conductivity, like copper

Methodology Applied

Scientific EffectElectrical conductivity: Conduction (electrical)

Data Source

PatentUS20250162725A1Lightning arrester for a low observable vehicle and same

Publication Date: 2025.05.22 AIRBUS DEFENCE & SPACE GMBH

AI summary

A lightning arrester for a low observable vehicle, in particular stealth aircraft, is proposed, comprising a support structure composed of a first metal alloy having high thermal stability and comprising a diverting structure composed of a second metal alloy having high electrical conductivity, the diverting structure being accommodated at least sectionally in the support structure; and a vehicle, in particular stealth aircraft, comprising at least one such lightning arrester is also proposed.