This rulemaking would amend certain airworthiness regulations for transport category airplanes regarding lightning protection of fuel tanks and systems by establishing design requirements for both normal conditions and possible failures of fuel tank structure and systems that could lead to fuel tank explosions, adding new maintenance requirements related to lightning protection features, and imposing specific requirements for airworthiness limitations in the instructions for continued airworthiness. It would also create performance-based standards for prevention of catastrophic fuel vapor ignition caused by lightning by regulating the risk due to both ignition sources and fuel tank flammability. This change would allow designers to take advantage of flammability reduction technologies whose effectiveness was not foreseen when earlier revisions to these rules were written. This change would also relieve some of the administrative burdens created by the current regulations.