Lightning strikes jets daily; serious consequences are rare

Some details about lightning strikes in civil aviation:

• Lightning strikes on passenger airliners occur daily, particularly in the Northern Hemisphere and the equatorial belt where massive thunderstorms are frequent throughout the year.

• Each large passenger jet — such as the Airbus A330 — is struck by lightning about once every three years on average, according to international aviation incident statistics.

• Regional aircraft are hit about once a year because they cruise at much lower altitudes where there's a greater possibility of strikes.

• With approximately 25,000 commercial jets in service with the world's airlines, there are statistically about three dozen lightning strikes occur each day.

• The overwhelming majority of such incidents ends with no damage or only superficial damage to the airframe, such as small dents.

• Most airliners — such as the A330 — are built mainly of aluminum, which is very good at dissipating the energy contained in a lightning bolt, which can be in excess of 300,000 amps.

• Composite components on some newer models are not as good at shedding electrical energy and are particularly prone to damage from lightning strikes.

• There have been only a handful of accidents in the past 50 years in which lightning may have played a contributory role.

• The deadliest occurred on Dec. 8, 1963, when lightning ignited the vapors in the fuel tanks of a Pan American World Airways Boeing 707 flying over Maryland. All 81 people on board died. Immediately after, the Federal Aviation Administration ordered that all commercial airliners be equipped with electrical discharge wicks.