Aircraft Telescopic Refueling Mast Lightning Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft telescopic refueling masts are vulnerable to lightning strikes and static discharges during refueling operations, leading to potential arcing and sparking that can ignite fuel vapors, while existing protection methods either allow lightning currents to flow or fail to manage static charge effectively.
Innovation Solution
The design incorporates a metallic structural beam connected to the aircraft with flexible conductive means, featuring a fixed and telescopic metallic tube, insulated and low-conductive components to divert lightning currents and drain static charges, ensuring safe electrical bonding and controlled discharge paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the fuel conduit is electrically isolated to prevent lightning currents, then arcing and sparking are prevented, but static charge accumulation occurs which can ignite fuel vapors
Solution Approach 1:
The patent applies different electrical conductivity properties to different parts of the fuel conduit system. The outer conduit is made of electrically conductive material to drain static charges, while the inner conduit is electrically isolated to prevent lightning current flow. This local differentiation of material properties allows simultaneous prevention of both arcing from lightning and static charge accumulation.
Solution Approach 2:
The fuel conduit system employs a composite structure with an inner electrically isolated conduit and an outer electrically conductive conduit. This composite design combines materials with different electrical properties to achieve dual functionality: protection from lightning strikes while enabling controlled static charge dissipation through the outer conductive layer.
2Ease of operation
If the telescopic mast is located at the rear part of the aircraft in zone 1B, then refueling operation is enabled, but the mast is exposed to severe lightning strikes with high current pulses
Solution Approach 1:
The telescopic mast is segmented into multiple telescopic sections that can be independently protected. Each section contains fuel conduits with electrical isolation measures, and the segmented structure allows for targeted application of protective measures at different locations along the mast, reducing overall vulnerability to lightning strikes while maintaining refueling functionality.
Solution Approach 2:
The patent implements preliminary protective measures by providing electrical isolation of fuel conduits and incorporating static charge drainage paths before lightning strikes occur. The conductive outer conduit and grounding arrangements are pre-configured to handle potential lightning events, ensuring protection is already in place when the mast is deployed at the vulnerable rear position.
3Reliability
If sealing joints are used in the telescopic mast, then fuel containment is achieved, but arcing and sparking can occur at these joints under lightning current stress
Solution Approach 1:
The patent introduces an electrical intermediary barrier in the form of insulating layers or non-conductive coatings at the sealing joints between telescopic sections. This intermediary prevents direct electrical contact and current flow across the joints, eliminating the arcing hazard while the sealing elements maintain fuel containment integrity through mechanical contact.
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
This solution effectively protects the refueling mast from lightning strikes and static discharges by diverting currents away from sealing joints and managing static charges, preventing ignition risks during refueling operations.
Implementation Method 1
conductive means providing a safe lightning current path and good electrical bonding for electrostatic discharge
Implementation Method 2
low conductive means for reducing the lightning currents at a safe level
Implementation Method 3
protection means against electric discharges, specially lightning strikes and electro-static discharges
Data Source
AI summary
An aircraft telescopic in-flight refueling mast comprising a metallic structural beam (31), electrically connected to the aircraft by flexible conductive means (33), having inside a fixed metallic tube (11) and a metallic telescopic tube (11) providing the fuel conduit, and, attached to said beam (31), flight control surfaces (41) and protection means against electric discharges, specially lightning strikes and electro-static discharges, including insulated means (39, 51) and low conductive means (15, 17) for reducing the lightning currents at a safe level and for draining the static charge created during the refueling, and conductive means (19, 21, 23, 33, 43) providing a safe lightning current path and good electrical bonding for electro-static discharge.