The use of composite materials for aircraft wing structures is steadily increasing. Lightweight and strong, they reduce weight, increase fuel efficiency, and are easy to shape, assemble and repair. Today’s advanced manufacturing methods help aircraft manufacturers build wings faster and more economically, which in turn, is increasing the demand for composites in the commercial aviation sector.
Composite material, however, is less conductive than the aluminum traditionally used in aircraft wings. This means that when lightning strikes an aircraft — a common occurrence, happening to virtually every plane during its service — mechanisms must be in place to mitigate its effect and protect critical equipment from combustion and damage.
In this blog we will explore:
To learn more about lightning-protection equipment requirements and new technologies, download our white paper, "Composite Materials for Aircraft Wing Structures Are Increasing the Need for Lighting Protection Equipment".
When lightning strikes, it usually makes contact at the fuselage, top and bottom of wing surfaces, and the tip of the vertical tail. A large amount of electricity is distributed over the entire surface of the aircraft. Without proper mitigation, energy can travel to fuel lines and create a dangerous arcing condition and potential explosion.
Aluminum, used in fuselage and wing construction, can readily conduct the electricity from the lightning strike. The current will move across the aircraft’s skin and pass back to the atmosphere. Composite materials do not possess the same conductive qualities. In order to take advantage of the benefits of composite materials, aircraft designers create and install light-weight metal mesh to a thick outer layer of fiberglass. This solution spreads the electrical charge over the aircraft’s exterior, away from combustible lines and components, and the interior carbon fiber body structure. Additionally, equipment is incorporated in order to mitigate the risk of arcing and combustion where sections of metal, joints and fasteners, for example, are connected to carbon fiber composite near areas of special concern, like fuel tanks.
Static dissipating tubes, also known as fuel and vent line isolators, play an integral role in controlling lightning’s energy flow. By allowing the fuel system architecture to have a resistance value higher than the outer composite structure, isolator tubes permit limited current flow to minimize arcing and allow static dissipation. Static dissipating tubes can serve as an extra safety measure for conventional metal aircraft as well.
As aircraft manufacturers increase the production of composite wings, lightning-protection equipment suppliers will need to streamline their productivity and invest in new manufacturing technology areas to add value for customers. Key areas of focus include:
Advanced robotic technology – can lower the costs and achieve zero defects for lightning protection equipment products while ensuring repeatability.
Additive manufacturing – also known as 3-D printing, reduces waste, speeds production, and enables designs.
Comprehensive testing services – must go hand-in-hand with the manufacturing process, beginning at the product development stage and continuing through the certification process.
Advanced simulation software – new software algorithms can precisely calculate load paths and lightning paths, helping aerospace engineers know exactly where to distribute composite fibers based on their strength and where to install connections and inline lightning dissipation components.
Aircraft manufacturers should look for partners that can collaborate with them in driving innovation, lowering operating costs, and delivering high-quality products that ensure safe flight. When researching a business partner's history, consider the following:
Financial stability - can the supplier meet rapid prototyping and production needs?
Equipment effectiveness – are their solutions consistent with industry-standard design and manufacturing expectations as well as safety and certification requirements?
Test and validation capabilities – are thorough testing methods followed to assure readied commercialization?
Manufacturing acumen – can the supplier produce a repeatable quality product in a continuous improvement environment?
Reduced installation and purchasing costs – is the supplier focused on improving efficiencies and reducing costs that will benefit the aircraft manufacturer?
Internal research and development – what is the investment and focus the supplier has on product improvements?
MRO and engineering support – does strong aftermarket support exist? Is it globally available?
A track record of excellence – who are the supplier’s customers and will they make them available to you to assess their level of satisfaction with the supplier?
A commitment to sustainability – does the supplier see itself as responsible for maintaining focus on the environment and needs of society while realizing the growth of its business?
As the use of composites in the aviation industry continues to expand, lightning-protection equipment suppliers will need to ensure they can keep pace with demand. To be successful partners, they will need to invest in new manufacturing technologies such as advanced robotics, additive manufacturing, testing services, and simulation software to streamline productivity and add value.
Parker Aerospace is dedicated to the safety of flight and offers a comprehensive array of lightning-protection equipment that is fully tested to the most stringent commercial and military regulations for lightning, fire, and flammability. Parker's lightning lab testing engineers are active members of the SAE A-2 Lightning Safety Committee.
Watch this video and learn about Parker's on-site testing capabilities.
To learn more about lightning-protection equipment products, requirements and new technologies, download our white paper, "Composite Materials for Aircraft Wing Structures Are Increasing the Need for Lightning Protection Equipment".
After more than a century of experience serving our customers, Parker is often called to the table for the collaborations that help to solve the most complex engineering challenges. We help them bring their ideas to light. We are a trusted partner, working alongside our customers to enable technology breakthroughs that change the world for the better.
This post was contributed by Glen Kukla, engineering team leader, Parker Aerospace, Fluid Systems Division.