2003 Flight Forecast - When Lightning Strikes

A thunderstorm can be a pilot's worst nightmare. Thunderstorms can cause delays in flights because pilots need to avoid their dangers. Airports also need to protect their ground crews that are getting baggage loaded and planes ready for take off and landing. After you read the information here test what you have learned by taking the Lightning and Flight Quiz.

How can pilots avoid a thunderstorm or lightning?
When there is danger on the ground, an accident or road construction, people driving in a car must take a detour and go a different way than they intended. The same thing happens in the air. Pilots will fly a different path and take a long detour to try to go around a bad thunderstorm. Sometimes they can fly up high and go above the storm.

But planes can't always avoid lightning. Lightning can strike miles away from the thunderstorm. Sometimes, in fact, an airplane that flies into a cloud that already has electrical charges built up in it can create a lightning stroke.

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.