How Does Aircraft Lightning Protection Work?

Lightning strikes are an everyday occurrence on Earth: on average, there are 100 strikes per second worldwide. Although about 80% of these lightning strikes are intra - or intercloud - lightning within the same cloud or between different clouds, they can still pose a risk to airborne objects, such as aircraft.That's why lightning protection for aircraft is critical.

Each year, aircraft are affected by lightning several times (1-4 times). Today, planes are protected, most strikes do little damage, and most of the time passengers don't even notice that planes have been hit.In fact, it has been more than 50 years since the last major accident caused by lightning: in 1967, a commercial jet crashed in the United States after a lightning strike caused a fuel tank to explode.

Today, various techniques and methods are implemented to reduce the threat of lightning. Find all the details about aircraft lightning protection here.

 Advanced composites are used throughout the body of an aircraft

How do you protect your aircraft from lightning?

Planes are protected from lightning in different ways. For one thing, most of their exterior parts are made of metal, thick enough to withstand lightning strikes. This "metal shell" provides basic protection for the aircraft, while also controlling electromagnetic energy into the aircraft's electrical wiring to keep it at a constant level without damaging the aircraft.

Second, the "skin" around the cabin and interior compartments is designed with metal mesh running through to provide an additional layer of protection. This conducts electricity through the outside of the ship, protecting the crew, passengers and electronics inside from any voltage. It acts as a Faraday cage, insulating the interior of the aircraft from electromagnetic fields.

Expanded Copper Mesh for Lightning Strikes Protection

In addition, some areas that are more likely to be struck by lightning may contain wire harness shielding, bonding zones, or some type of composite component, such as expansion foil, copper wire mesh, aluminum foil coating, embedded wire, metal picture frames, diversion strips, etc.

This protection is evolving all the time.Based on data from lightning strikes on aircraft in service, manufacturers improve and develop lightning protection for aircraft to reduce damage.

Newer planes such as the Boeing 787 and Airbus A350, for example, use a higher proportion of composite materials such as carbon fiber, which reduces the electrical conductivity of the fuselage and wings.In addition, the manufacturer has developed a solution to add more metal wires to the composite to ensure good electrical conductivity on the outside of the aircraft.

Although prepared to withstand a lightning strike, planes must be thoroughly checked when they are hit by bolts.

Expanded Copper Mesh for Lightning Strikes Protection

Carbon / epoxy composites are widely used in aviation due to their high strength, fatigue resistance and corrosion resistance. Aiming at the damage of carbon / epoxy composites during aircraft lightning strikes, a three-dimensional finite element model of carbon / epoxy composite laminates protected by copper mesh and aluminum mesh was established, and the lightning ablative element of composite structure was treated by element deletion method. The lightning protection effect of copper mesh and aluminum mesh was verified under different current peaks and different grid spacing, and the relationship between the weight change of the metal mesh and the lightning protection effect was studied. The test results show that the ablation area and damage depth of the composite laminate with metal mesh protection are significantly reduced. The denser the grid spacing is, the better the lightning protection effect is. The copper mesh composite laminate has better protection effect than the aluminum mesh. With the weight of the metal mesh increases, the degree of lightning damage to the composite laminate decreases.