This is what happens when lightning hits plane

When lightning strikes a plane, passengers may see bright flashes through the window, followed by a loud rumble. Briefly cabin lights probably will blink.
A similar event is not at all uncommon. In the US alone each airliner is struck by lightning once a year.
Usually flash enters through the nose and out of the machine through the tail. This means that the charge passes through the body of the plane.
A flash is approximately 5 times hotter than surface of the sun. These high temperatures can cause serious damage to the aircraft. The last time, however, in that plane (in the US) crashed because of a similar thing in 1963
Today, these machines are designed to withstand lightning strike. Also conducted long and ground tests before ever taking off.
During their construction planes are coated with a conductive outer layer. Typically aluminum. It allows the flash to pass freely through the machine and back into the atmosphere. At the same time protects the sensitive instruments on board.