Ask A Scientist© Weather Archive

> >>  name       Mark
> >>  status     other
> >>  age        20s
>
> >>  Question - What effect does lightning have when it strikes an aircraft?
>
>
>Mark,
>
>A lightning strike on an aircraft normally does not damage the
>airplane, although it may leave a burn mark. The lightning
>energy travels through the metal skin of the aircraft and
>sometimes into other areas of the aircraft. In a few cases
>the energy has damaged electronic equipment in the aircraft,
>but only a few aircraft have received enough damage to cause
>a major problem with flying the plane. The skin of the aircraft
>can usually dissipate the lightning energy sufficiently to prevent
>problems.
>
>David Cook
>Lightning researcher at Argonne National Laboratory


=========================================================
Dear Mark-
>
>Lightning can have varying effects on an airplane, ranging from "no" effect,
>to severe damage, and even in extremely rare instances, explosion is fuel
>tanks. Since the exterior or "skin" of most aircraft is metal, the
>electrical charge of the lightning bolt travels along the surface of the
>aircraft and exits, causing only minor damage, such as pits or burns on the
>skin at the points of entry or exit. Occasionally the lightning can damage
>other parts of an aircraft, such as the electrical or avionics systems.
>
>Aircraft are required to remain at least 20 miles from thunderstorms, mainly
>to protect them from hail and turbulence, but also from lightning. But those
>first two components of a thunderstorm cause much more damage to aircraft
>than lightning does.
>
>Wendell Bechtold, meteorologist
>Forecaster, National Weather Service
>Weather Forecast Office, St. Louis, MO
========================================================
>Mark -
>
>It is unlikely that an aircraft would be struck by lightning. On the ground it
>sits on rubber tire (like a car). In the air, it is not grounded. When
>lightning strikes an airplane, it is just a matter of bad luck - being in the
>wrong place at the wrong time. In other words, if it happens to be between two
>points between which the lightning is already going to strike the current will
>go through the airplane.
>
>When it does happen, the consequences can be dire. Electrical circuits
>(especially the in the micro-electronics employed in the most modern systems)
>are damaged just as a tv or microwave oven would be. Sometimes, parts of the
>airplane can be blown off and holes cut in aluminum. Seldom does a lightning
>strike cause a crash, but the potential is there.
>
>Related to this, aircraft can pick up a static charge by flying through 
>charged
>air. When they return to the ground, they can hold the charge for a
>considerable time sitting on their rubber tires. A real danger exists if the
>charge sparks when refueling. They solves this in two ways. By electrically
>connecting the fuel truck and the plane before fueling and by attaching 
>"static
>wicks" to the trailing edges of aircraft that allow the charge to dissipate
>more quickly.
>
>Larry Krengel
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