Planes don't actually avoid lightning; they are designed to withstand lightning strikes safely. The primary method of protection is based on the concept of the Faraday cage.
The Faraday Cage: A Plane's Shield
What is a Faraday Cage?
- A Faraday cage is an enclosure made of conductive material, typically metal.
- It works by distributing electrical charge across its surface, preventing the charge from entering the interior.
- This principle, discovered by Michael Faraday in 1836, is crucial for aircraft lightning protection.
How It Protects Aircraft
- The aircraft's outer skin, predominantly made of aluminum, acts as a Faraday cage.
- When lightning strikes a plane, the electrical current travels through the conductive skin and then safely exits the aircraft, usually through a wingtip or tail.
- This ensures that the electrical charge does not penetrate the interior and harm passengers or sensitive electronics.
Details of Aircraft Lightning Protection
Design and Materials
- Aircraft are designed with lightning protection in mind, with conductive pathways and bonding to ensure the current flows safely through the aircraft structure.
- Composites are also used in modern aircraft. These are equipped with an embedded conductive mesh that replicates the Faraday cage effect.
Testing
- Before an aircraft is approved for flight, it is rigorously tested in labs.
- Tests include subjecting it to high-voltage electrical discharges, simulating real lightning strikes to prove its lightning protection capability.
Examples of Lightning Protection in Action
- When a plane is struck by lightning, you might see a bright flash, hear a loud bang, and even see a brief electrical discharge on the plane's exterior.
- Inside the cabin, the passengers and crew might notice little more than the sound and flash. The Faraday cage protection is doing its job by diverting the electrical charge away from the interior.
| Feature | Description |
|---|---|
| Principle | Faraday cage |
| Material | Mostly aluminum or composite materials with embedded conductive mesh |
| Mechanism | Distributes electrical charge across the aircraft's exterior, safely discharging it through external components |
| Outcome | Protects interior and passengers from electrical damage. |
By leveraging the principle of the Faraday cage, aircraft are designed to safely handle lightning strikes, making air travel incredibly safe.
