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? Here we can see the answers to these questions and more.
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.
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.
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?
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 aeroplanes 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 aeroplane. These meshes also help prevent the buildup of electric current in any one area. Carbon fibre, fibreglass, aluminium, and copper are all commonly used in this protective mesh that is as thin as a window screen.
Aircraft Lightning Protection on the Ground
But what happens when lightning strikes an aeroplane 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
The best way to protect the ground crew from lightning strikes is with a total lightning detection system.
The right lighting 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 refuelling the plane will best receive alerts through a strobe light rather than a 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 the ground crew from lightning with detailed, practised safety procedures. Airport safety lightning policies should outline how to secure at-risk infrastructure and move personnel to safety quickly.
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 the 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.
Is lightning dangerous for aeroplanes?
Experts estimate that on average, lightning hits aircraft once per year or once every 1,000 hours of flight time. The last incident when a lightning strike ended in a catastrophe occurred in 1963. The lightning-caused a crash of a Pan American Boeing 707 in Maryland, the U.S. and 81 passengers died on board.
What happens if lightning hits a plane?
When lightning hits an aircraft, it arcs through the fuselage, from the wings and nose, and exits through the tail. All wires onboard are grounded or isolated away from the body, and the electric current passes through the conductive outer shell of the aircraft.
How is a plane protected from lightning strikes?
Since the outer skin of most aeroplanes is primarily aluminium, which is a very good conductor of electricity; the secret to safe lightning hits is to allow the current to flow through the skin from the point of impact to some other point without interruption or diversion to the interior of the aircraft.
Can planes fly in heavy rain?
Rain is not actually dangerous to aircraft, and you can often fly through the rain with no issues at all. The main problem is that heavy rain often leads to poor visibility.
Why do planes not fly in the fog?
The reason why an automatic landing is conducted in foggy conditions is down to the need for the aircraft to be flown incredibly accurately down to a very low altitude when the pilot can't actually see the runway.
How many planes get struck by lightning a year?
Even though lightning activity can vary by geographic location, its frequency is such that, according to the International Air Transport Association (IATA), an aircraft is struck by lightning every 1,000 flight hours, the equivalent of one strike per aircraft per year.
Lightning protection on aeroplanes may include:
Wire bundle shields.
Ground straps.
Composite structure expanded foils, wire mesh, aluminium flame spray coating, embedded metallic wire, metallic picture frames, diverter strips, metallic foil liners, coated glass fabric, and bonded aluminium foil.
Here are some tips to keep safe and reduce your risk of being struck by lightning while indoors.
Avoid water. ...
Avoid electronic equipment. ...
Avoid corded phones. ...
Avoid windows, doors, porches, and concrete.
Why do planes not get struck by lightning?
Aeroplanes are designed to withstand hundreds of thousands of amperes of electricity—far more electricity than a lightning bolt can deliver. ... The electricity follows the outer surface of the plane's frame and then jumps back into the air, thanks to little antenna-like devices called static wicks.
What is the 30-30 rule for lightning safety?
Lightning 30/30 rule: If it takes less than 30 seconds to hear thunder after seeing the flash, lightning is near enough to pose a threat; after the storm ends, wait 30 minutes before resuming outdoor activities.
Lightning strikes the Earth approximately 25 million times per year, according to a report published by The Weather Channel. With temperatures reaching up to 1800 degrees Fahrenheit, these strikes can cause serious damage, igniting homes, structures, trees and more. But why aren’t aeroplanes affected by lightning strikes? With some 5,000 aeroplanes flying over United States airspace at any given time, conventional wisdom should tell you that at least some would get struck by lighting.
