How Does Aircraft Lightning Protection Work?

  • Dec 12, 2019

stationary aircraft on a tarmac

Aircraft lightning protection keeps passengers from realizing their plane was hit, but how does it work? Is there lightning protection for ground operations? Are there any aircraft lightning protection limitations? This blog is your one way ticket to the answers to these questions and more.

Please prepare for takeoff and keep your eyes fastened to this page until we’ve safely landed at the conclusion!

Lightning Striking Airplanes

Before we get into aircraft lightning protection, it’s important to understand why it exists. These tools, systems, and policies are necessary because lightning often strikes planes both in the air and on the ground.

plane flying through a partly cloudy ski at sunset

Lightning Strikes are Common

At any given moment, there are approximately 100 lightning bolts happening throughout the world. Lightning strikes are an everyday occurrence on planet earth. And while approximately 80% of those strikes stay in the clouds (in-cloud lightning), they still pose a risk to airborne objects, like planes.

Where did lightning strike the most in 2019? Take a closer look at lightning activity in the U.S. >Read the Report<

So just how often does lightning strike planes? For commercial jetliners, the answer to that question is about once per year. It sounds like a lot, but it’s the truth! The United States Federal Aviation Association (FAA) estimates that lightning strikes a commercial plane once every 1,000 flight miles.

Most of these strikes do little-to-no-damage and passengers don’t even know the strike happened. There are times when lightning damages planes, but it certainly isn’t the norm.

Where Does Lightning Strike?

airplane flying through a blue sky over the clouds

It doesn’t matter if your aircraft is on the ground or in the air. Lightning typically strikes through one of four external places:

  • Wing
  • Tip
  • Nose
  • Rudder

 

While lightning strikes can happen on the ground, a survey of U.S. commercial jets showed that most lightning strikes occur between altitudes of 5,000 and 15,000 feet.

A majority of lightning striking aircraft incidents also occur when the plane is in the same cloud as the lightning, rather than below, above, or beside the cloud.

Planes are also the perfect target on the ground. Airports are big, open spaces. Oftentimes, the rudder will attract lightning which can then pose a threat to the aircraft itself and nearby ground crew members.

Aircraft Lightning Protection in Air

Why don’t most people know when lightning strikes their plane while in the air? It all comes down to built-in aircraft lightning protection in the form of metal.

Most airplanes have a thick, external metal that is sufficiently thick enough to resist lightning strikes.

The thick exterior metal prevents a lightning strike’s electromagnetic energy from entering critical spaces, including:

  • Interior of aircraft
  • Electrical wires

 

Sometimes a little electromagnetic energy will enter the electrical wires, but it typically isn’t enough to reduce energy to a dangerous level.

Commercial aircraft providers also implement extra aircraft lightning protection measures in the areas most likely struck, such as the nose, tip, rudder, and wings. Common commercial aircraft lightning protection methods besides metal framing include:

  • Avionics and flight control protection
  • Conductive meshes

 

Let’s divert our flight and talk about these two aircraft lightning protection methods.

Avionics & Flight Control

aircraft lightning protection in the avionics and flight control area

Lightning strikes can easily destroy avionics and flight control systems, even with thick metal exteriors. Why doesn’t it? Today’s engineers install effective surge protection devices around these systems with shield wiring around the plane.

There are other lightning protection measures engineers use to prevent a surge, such as properly grounded wingtip lights.

Conductive Meshes

Engineers use conductive meshes to help minimize damage to the skin of the airplane. These meshes also help prevent the buildup of electric current in any one area. Carbon fiber, fiberglass, aluminum, and copper are all commonly used in this protective mesh that is as thin as a window screen. Pretty cool, right?

Aircraft Lightning Protection on the Ground

But what happens when lightning strikes an airplane on the ground?

While these aircraft lightning protection systems continue to work while planes are on the ground at an airport, lightning striking the grounded plane isn’t the real risk. When it comes to lightning risk at airports, ground crew members are in the most danger.

While engineers design planes to handle the force of most lightning strikes, ground crew members often go unprotected. Luckily, there are tools, systems, and protocols available to airport operations to protect these vital members of their crew.

Ground Crew Lightning Protection

ground crew working on a plane at sunrise

The best way to protect ground crew from lightning strikes is with a total lightning detection system.

The right lightning solution for overall safety and operations has a three-step approach:

  1. Detect
  2. Alert
  3. Protect

 

Airport lightning safety starts with accurately detecting total lightning, which is the combination of in-cloud and cloud-to-ground strikes. While cloud-to-ground strikes are the only ones that can injure people on the ground at airports, in-cloud lightning is a dangerous precursor to severe weather like microbursts, hail, and tornadoes.

Once airports, airlines, and fixed-based operators (FBOs) have reliable detection systems in place, they then must be able to alert the right people. At a busy airport, alerting technologies might be different for various stakeholders.

For example, ground crews refueling the plane will best receive alerts through a strobe light rather than text message. On the other hand, air traffic control would better benefit from a real-time lightning strike map.

Once these two areas are taken care of, it’s time to protect ground crew from lightning with detailed, practiced safety procedures. Airport safety lightning policies should outline how to secure at-risk infrastructure and move personnel to safety quickly.

Click here to read our detailed Ultimate Lightning Guide for Airport Operations

Aircraft Lightning Protection: Prepare for Landing

Isn’t it amazing how lightning can strike a plane without passengers knowing? Built-in aircraft lightning protection is an extremely important advancement in aviation technology that provides safety and continuity to aviation professionals.

But lightning risk isn’t limited to the air. It’s important to know that aircraft and ground crew alike are in danger on the ground, too. Aircraft lightning protection should be a term that really encompasses both in-air and on-ground activities. Airports, airlines, and FBOs should prioritize both for a comprehensive weather safety plan.

Before we take off the “fasten seatbelt” light, we’d like to show you how JetBlue Airways handles aircraft lightning protection on the ground with detecting and alerting technology from Earth Networks.

 

Questions? Leave them in the comments below and stay safe!


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