Landing Gear Lightning Arrester Cowl for Taxiing Actuator Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Aircraft landing gear components, particularly the electric taxiing actuator, are vulnerable to lightning strikes due to relocated metallic hydraulic and electrical cables outside the wheel perimeter, necessitating effective lightning protection.

Innovation Solution

Aircraft landing gear with a surge arrester hood featuring a rigid mechanical connection, grounding braids, and an insulating matrix made of fiberglass and/or carbon-epoxy resin, which accommodates flexible lines and minimizes lightning paths through hinged or sliding sections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If metallic hydraulic lines and electrical cables are relocated to bypass the actuator housing, then the actuator can be installed between the wheels, but the cables become susceptible to conducting lightning strikes into the aircraft's electrical system

Engineering Contradiction:
Improveactuator installation capabilityVSAvoidlightning strike vulnerability
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A surge arrester hood is introduced as an intermediary protective element between the lightning strike source and the electrical cables. The hood acts as a shield that intercepts lightning strikes and provides a controlled path for discharge, preventing direct strikes to the cables while allowing the cables to be routed outside the wheel perimeter for actuator installation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the landing gear components are positioned outside the wheel perimeter for actuator installation, then the actuator can function, but the components are exposed to lightning strikes

Engineering Contradiction:
Improveactuator functionalityVSAvoidprotection against lightning
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The surge arrester hood is installed in advance as a protective measure before the lightning strike occurs. The hood is pre-positioned to cover the electrical cables and actuator area, establishing a protective barrier that will intercept and channel lightning strikes away from vulnerable components, ensuring reliability while maintaining actuator functionality.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If rigid electrical connection means are used between the hood and actuator, then grounding is improved, but the system becomes less flexible during aircraft movement

Engineering Contradiction:
Improvegrounding effectivenessVSAvoidflexibility during movement
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The solution merges rigid and flexible connection elements by combining rigid mechanical mounting structures with flexible grounding braids. The rigid mounting provides stable structural support and electrical connection, while the flexible grounding braids maintain reliable electrical grounding even when the landing gear moves or flexes during aircraft operation, thus achieving both reliability and adaptability.

Inventive Principle:
Principle #5Merging (Combining)

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

Provides robust lightning protection for the actuator by reducing the electrical path length and ensuring effective grounding, even during aircraft movement, thus safeguarding the electrical system.

Implementation Method 1

a first grounding braid extending between the grounding conductor and a first connection point on the surge arrester hood

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The production of the hood is particularly economical when the insulating matrix includes fiberglass and/or when the insulating matrix includes carbon and/or epoxy resin

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP4153479B1Landing gear comprising a lightning protection
Publication Date: 2025.11.12 SAFRAN LANDING SYSTEMS
  • EP4153479B1 patent drawingFigure 1
  • EP4153479B1 patent drawingFigure 2
  • EP4153479B1 patent drawingFigure 3~4

AI summary

Disclosed is landing gear (100) of an aircraft (1000) comprising a pair of wheels (5) between which an electric actuator (10) at least partially covered with a lightning arrester cowl (20, 40) is placed, the lightning protection cowl (20, 40) comprising an insulating matrix (25) onto which at least one electrical conductor is attached, the electrical conductor (26, 60) comprising electrical connection means (27, 28) for connecting the electrical conductor to a ground conductor (90) of the aircraft (1000).