Boeing 787 Withstands First Lightning Strike as Tests Advance
The jet was flying last month above Puget Sound, near Seattle’s Boeing Field, when it was hit unexpectedly by a lightning bolt during a rare thunderstorm in the area, Fancher said yesterday in a telephone interview. The aircraft’s systems, fuselage and wings all appeared to be unscathed, he said.
“Post-flight inspections revealed absolutely no damage,” said Fancher, who took over the Dreamliner testing program in December 2008. “I walked around the airplane an hour after it landed and you couldn’t tell a thing had happened.”
Engineers are still studying how lightning affects the 787, the first jetliner to be built mostly from composite materials instead of traditional aluminum. The Dreamliner is more dependent on electricity for controls and other systems, with power levels five times higher than on Boeing’s 767.
Scheduled lightning-strike simulations and tests, mostly on the ground, are planned later this year as Chicago-based Boeing completes the U.S. certification for the plane to carry passengers, Fancher said.
“This was not on the test program, but it was great that it happened,” said Hans Weber, president of San Diego-based aviation consulting firm Tecop International Inc. “Any time you want to demonstrate an airplane can withstand lightning, the best thing is to show that it actually did so.”
The average jetliner gets struck by lightning once a year, said Weber, who has advised the U.S. Federal Aviation Administration.
Lightning poses a threat in flight because it can damage a plane’s structure or internal controls. In 1998, a US Airways Group Inc. Fokker F-28 had to make an emergency landing after a strike caused electrical arcing that melted holes in the plane’s hydraulic system. The National Transportation Safety Board concluded the plane needed better lightning protection.
The Dreamliner struck by lightning last month was the first of five 787s in the flight-test program. The sixth and final jet will fly next month, Fancher said.
Crews have finished 40 percent of the so-called test points needed for FAA approval during more than 1,000 hours of flying since the plane’s maiden flight in December, Fancher said. The first delivery, to Japan’s All Nippon Airways Co., will come “several weeks” after the FAA acts and is on target for year- end, he said.
The 787 is more than two years behind schedule amid Boeing’s struggles with new materials, parts shortages, redesign work and a new manufacturing process that relies more on suppliers. The plane’s 860 orders valued at $148 billion have made the Dreamliner Boeing’s best-selling new model.
The first 787 with General Electric Co.’s GEnx engines made its debut flight yesterday, staying aloft for 3 hours and 48 minutes above Washington state, home to the planemaker’s commercial manufacturing hub. The first four test jets are equipped with engines from Rolls-Royce Group Plc.
Boeing has promised that the 787 will be 20 percent more fuel-efficient than comparable jets, thanks to the lighter- weight carbon-fiber construction of the fuselage and wings, new engines and the greater use of electricity for power.
Engineers are starting to collect performance data from the test flights and will release details “fairly soon,” after independent reviews verify the analysis, Fancher said.
“We have found almost no areas where the airplane has performed any different than we expected,” said Fancher, who led four major military flight-test programs for Boeing before taking on the Dreamliner. “It’s meeting our modeling predictions very accurately.”
Boeing test pilots, who are now flying under FAA supervision, have taken the 787 as high as 43,000 feet (13,106 meters) and traveled as fast as Mach 0.977 during a dive, or almost the speed of sound, Fancher said.
The Dreamliner may make its public debut next month, at the Farnborough air show in England, provided the tests are going well enough that a plane can be spared, Fancher said.