Dec. 13, 2007 — -- In the summer of 2000, sisters Maria Ferrante and Jan Raslavsy were flying home from a family reunion when their plane was struck by lightning.
"I heard a gunshot," said Ferrante. "The whole plane just went over a foot, immediately."
Her sister described turbulence, then some light, similar to a flash.
"I just remember this very young flight attendant being terrified -- which isn't very comforting," Raslavsy said.
It might be even less of a comfort to know that, on average, each commercial airplane gets struck by lightning once a year. But could lightning actually bring down an airplane?
"We'd like to believe today that lightning cannot take down an airplane," said Andy Plumer, chief engineer at Lightning Technologies in Pittsfield, Mass. "But in the past, it has happened."
From the 1940s to the 1960s, Plumer said, "there were plane crashes, there were fuel tank explosions, there were effects on electronic systems … and that happened more frequently than we care to remember."
So, it is not a myth. Lightning can take down airplanes.
In the late 1970s, NASA launched a project to study lightning strikes on airplanes.
Bruce Fisher signed on as lead researcher and learned there is really only one way to conduct such a study: Fly directly into a thunderstorm and try to get struck by lightning.
"Better than sitting at a desk and doing computations," said Fisher. "The lightning was the fun part of the mission. ... You know, we would go up and go down, plus or minus 3,000 or 4,000 feet with the updrafts and the downdrafts and allow the aircraft to do that."
The NASA Storm Hazards project flew into nearly 1,500 thunderstorms and experienced more than 700 lightning strikes. Fisher's test plane was hit more than 200 times … but it never crashed, thanks largely to its metal frame. When lightning struck, the metal conducted the electricity along the outside.
The point of the project, of course, was not merely to seek cheap thrills.
"We tried to quantify the electromagnetic properties of lightning strikes to aircraft," said Fisher.
To protect commercial aircraft from lightning strikes -- particularly as the technology changed -- they needed to know where lightning would strike airplanes, how often, and how much electric current it carried. In the process, Fisher discovered something shocking.
"Almost all lightning strikes to aircraft are triggered by the aircraft's presence."
When airplanes fly into charged pockets of air, the sharp points on the plane -- the nose, the wing, the tail -- concentrate the electric fields and create a channel for the lightning strike.
Fisher's research made it possible for engineers like Andy Plumer to capture lightning in a bottle, so to speak. Thanks to the data NASA gathered, Plumer created simulated lightning strikes that carry the same properties as those actually experienced in flight.
This is especially important because the next generation of aircraft will be made of carbon reinforced plastics, which, while lighter and stronger, do not conduct electricity as well as metal. To keep planes safe from lightning, engineers have to develop new methods to diffuse that destructive force. In one case, adding a layer of copper mesh to the hull of an aircraft can protect it from lightning.
The copper mesh is "very thin, very lightweight," said Plumer, "but it provides an amazing amount of lightning protection."
Thanks in large part to these efforts, no commercial airline has crashed in the United States because of a lightning strike since 1963.
So while you may remain a nervous flier, you can fly a little easier knowing that scientists like Bruce Fisher and Andy Plumer have made the threat from lightning a blast from the past.