Fear of Flying - Thunderstorm and lightning

November 15, 2011

Now, lets talk about the danger of flying right into the middle of the biggest and meanest thunderclouds. No competent pilot would ever do that deliberately.

What are the dangers of a thunderstorm to a plane?

Thunderstorms can have very strong winds called updrafts and downdrafts that cause what is called turbulence. Turbulence makes it very difficult to control the airplane. Wind from a thunderstorm near the ground can also be very dangerous to planes. These winds can change speed and direction quickly. These winds are called wind shears. During bad storms there may be hail stones. These can break the plane’s windshields and damage the plane and its engines. Heavy rain can sometimes get into the engine and cause it to fail. Lightning at the height the plane is flying can be very bright and it might even temporarily blind the flight crew.

Can Lightning strike a plane?

Lightning does hit airplanes and when it does it can damage the electronic equipment needed to fly the plane. Lightning research done during the 1980s by NASA had an F-106B jet fly into1,400 thunderstorms and lightning hit it over 700 times. The lightning did not damage the airplane but scientists found out that it could damage electronic systems on the plane. This led to requirements that all aircraft electrical and electronic systems have built-in lightning protection.

What has been done to keep planes safe from lightning?

At any given time there are more than 2,000 thunderstorm throughout the world, producing 100 flashes of lightning per second. Planes can not totally avoid lightning and thunderstorms but due to learning more about severe thunderstorms and how they might affect the safety of those in flight, scientists and engineers have helped developed ways to make flights safer.

Many planes have their outer areas (called skins) made from aluminum. This is a metal that is a very good conductor of electricity. If lightning strikes the plane, most of the lightning current remains on the exterior of the aircraft and flows along the exterior and then away from the plane. Newer airliners are being made of composites which do not conduct electricity as well, but the outer skin is embedded with a layer of conductive fibers designed to carry the lightning currents.

Systems have been designed to help protect all of the computers and instruments that control everything in the airplane. Lightning protection engineers make sure that damaging surges can not reach the equipment inside the aircraft. Shielding, grounding and surge suppressions devices are used to help protect cables, circuits, and equipment. Every piece of equipment that is essential to a safe flight and landing of an aircraft must be tested and certified that it is protected against lightning. The Federal Aviation Administration (FAA) sets the standards and put the regulations in place.

In addition, we now have more sophisticated instruments to help detect lightning and predict weather conditions. Doppler radar is weather radar that measures the direction and speed of a moving object, such as drops of precipitation. This can help those in the airport’s flight control centers know where the storms are located. Lightning detection networks have also been developed which can track lightning strikes all over the country using the National Lightning Detection Network. This network uses magnetic sensors and computers to detect when and where lightning strikes. If a supercell (the most dangerous type of thunderstorm) is spotted, pilots and airport personnel are alerted

Even though the passengers and crew may see a lightning flash and hear a noise if lightning strikes their plane, nothing serious should happen because of the lightning protection built into the aircraft. Pilots sometimes report a temporary flickering of cabin lights or some brief interference with their instruments.

Smaller planes are probably struck less frequently by lightning because of their small size and because they often avoid weather that might include severe thunderstorms and lightning. Larger airliners may delay flights to protect passengers and flight crew as well as ground crews that are handling baggage or preparing planes for departure. Once in the air, pilots often fly detours or change altitude to avoid severe storms and the turbulence or lightning.

The plane is designed to withstand lightning strikes.

In fact, you are in more danger while disembarking the aircraft than you are experiencing a mid-air strike. Watch the video again to see that the plane is fine. It doesn’t start to fall from the sky, it doesn’t alter course, and it doesn’t catch fire.

So, how do aircraft withstand such a violent force of nature?

Planes are designed with every single metal part wired together, to allow the electricity to pass through and exit via ‘static discharge’ wicks on the wings and the tail. The electrical charges just traverse the length of the aircraft and exit through the static wicks at the trailing edges of the flaps or tail plane. The next time you happen to sit by a window seat behind the wings, just look out for these static wicks. They are like painting brushes with fine hairs sticking out, at the end of the flaps.

If you are a science student, you would remember the Faraday cage principle. Faraday was a scientist who discovered that, if you put electricity through a metal cage, no matter how strong or high the voltage is, anything inside the cage is totally protected from the electricity. The airplane cabin or a car body is similar to the Faraday cage. So don’t worry, you are safe in a lightning strike in an airplane just like you would in your car!

Thunder clouds are bumpy. It’s as simple as that. All airlines will aim to give you the most comfortable ride possible. Therefore, we will fly around thunderstorms to ensure that you remain comfortable – and don’t spill your coffee. Sometimes, while flying at night you will see lightning, but just remember that the light passes through the cloud – which makes it look much closer than it is.

The majority of lightning strikes that occur are during the early and latter stages of flight. In fact, an aircraft can sometimes cause lightning by flying close to an electrically charged cloud. The aircraft simply acts as a huge, floating, lightning conductor. Notice in the video above how the strike comes from the back of the aircraft, and continues on it’s course towards the ground.

In the event of a particularly violent storm, a pilot will choose to avoid taking off or landing as an extra safety precaution. We hope that this video and explanation helps with your fear of flying in thunderstorms.

It is true that small, general aviation airplanes have often gotten destroyed in thunderstorms, all because the pilot was flying in the clouds and, not having on-board radar to distinguish a thunderstorm from the surrounding clouds, inadvertently flew right into a big thundercloud.

But commercial aviation has a far happier history. Dispatchers who plan the flights will route flights away from thunderstorms. Sometimes they will even cancel flights because of thunderstorms. Pilots of commercial aircraft also have on-board radar to spot and avoid thunderstorms, and they will often request a course change to avoid bad weather. So, if your flight is delayed or cancelled because of weather, be grateful, not angry.