Results of investigation to develop a technological basis for overcoming aircraft lightning-strike hazards associated with turbojet aircraft fuel vents are discussed. Flame propagation and arrester experiments were performed with high-voltage and high-current facilities and repeated in a combustion research facility using a drive tube to simulate impulse effects of natural lightning. Flame propagation through actual aircraft vent systems containing flammable fuel-air mixtures was demonstrated, and characteristic flame propagation properties were measured and duplicated in laboratory apparatus. Preliminary assessment of problems involved in designing effective flame arresters and explosion suppression systems was made. Lightning-stroke patterns in fuel vent region were analyzed as to inferable hazard significance.