CFR /  Title 14  /  Part 25  /  Sec. 25.954 Fuel system lightning protection.

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]