FAA Concerned Lightning Could Cause 777 Explosions

The FAA has issued an update to an AD on hundreds of Boeing 777s because it’s concerned they might explode if struck by lightning. The AD was issued this week to update earlier action to address cracks in wing chords. When it reviewed the wing problems, the agency discovered that there were errors in the AD relating to the replacement of cap seals on fasteners in a section of the wing that penetrates the center fuel tank.

“If these seals are not replaced properly, and the associated fastener has poor electrical bonding to the airplane structure for any reason, the fastener may spark during a lightning strike and cause a fuel tank explosion,” the FAA said in the AD. The agency said it expects the AD to apply to 291 U.S.-registered aircraft.