The fuel system must be designed and arranged to prevent the ignition of fuel vapor within the system by --
(a) Direct lightning strikes to areas having a high probability of stroke attachment;
(b) Swept lightning strokes to areas where swept strokes are highly probable; and
(c) Corona and streamering at fuel vent outlets.
[Amdt. 25-14, 32 FR 11629, Aug. 11, 1967]