On average, every airliner gets struck at least once per year by lightning and passengers rarely ever know it happens. Watch these airliners get blasted by electricity as they approach Seattle-Tacoma International Airport on a dark and stormy night.
Strikes to airplanes are relatively common but rarely result in a significant impact to the continued safe operation of the airplane. According to Air & Space Magazine, an aircraft can safely pass through lightning as the airplane's aluminum hull conducts the charge harmlessly from entry point to exit, and the last crash in the United States due to lightning happened way back in 1963.
Ironically, aircraft made primarily of carbon fiber composites, like the Boeing 787, require the addition of metal to the fuselage to ensure proper lightning protection. Nose cones of most airliners are made of a composite material as to not interfere with the onboard radar equipment. The cones employ the use of thin metallic strips that act as diverters in the event lightning attaches to the front of the aircraft.
Sensitive electronic equipment like radio and navigation devices are designed with surge protection devices to avoid any damage due to an electrical spike. Additional shielding on wiring that may provide flight control data for fly-by-wire technology is also required.
Boeing has a vested interest in the effects of lightning on aircraft because the result of a strike can range from no damage to serious damage that requires extensive repairs and can take the airplane out of service for an extended period of time. Boeing has determined that the majority of strikes on jets occur while in clouds during the climb and descent phases of flight, which is verified in the following video. By understanding the effects of lightning they can develop ways to prevent or reduce damage and offer an aircraft that is safer and requires less maintenance.