787 Dreamliner survives first lightning strike

Boeing's 787 Dreamliner survived its first lightning strike virtually unscathed, providing the first in-flight test of its newly developed lightning-protection system.

The jet was struck last month during a thunderstorm near Boeing Field. Scott Fancher, head of the 787 program, told Bloomberg News Thursday that the aircraft's systems, fuselage and wings all appeared to be undamaged after the strike.

On today's metal airliners, lightning typically dissipates across the metal body of the airframe, then discharges to earth with relatively little damage. Because the 787 is the first airliner made largely from less-conductive carbon-fiber, Boeing had to design special lightning protection to avoid severe local damage at the location of a strike.

Engineers paid special attention to the 787 wing fasteners, to avoid gaps that could cause sparking in the wings' fuel tanks during a lightning strike.

And they embedded a thin copper mesh beneath the outer layer of the airplane's skin to disperse the current from a strike.

In the early design, that mesh was to cover the entire airplane structure. To save weight, the wire-mesh coverage was later restricted to the three areas where lightning commonly strikes an airplane: the nose, wings and tail.

Last year, Mike Delaney, chief project engineer on the 787, said it was highly likely the jet would suffer lightning strikes during flight tests. In order to reassure the public, "My personal wish is that these test airplanes get struck a lot," he said.

Dreamliner program spokeswoman Yvonne Leach said Friday the remaining flight test program will include lightning-strike simulations and tests, mostly on the ground.

But "we won't intentionally look for lightning in the sky," Leach said.

Dominic Gates: 206-464-2963 or dgates@seattletimes.com