FAA Federal Aviation Regulations (FARS, 14 CFR)

Each coolant tank must be tested under §23.965, except that --

(a) The test required by §23.965(a)(1) must be replaced with a similar test using the sum of the pressure developed during the maximum ultimate acceleration with a full tank or a pressure of 3.5 pounds per square inch, whichever is greater, plus the maximum working pressure of the system; and

(b) For a tank with a nonmetallic liner the test fluid must be coolant rather than fuel as specified in §23.965(d), and the slosh test on a specimen liner must be conducted with the coolant at operating temperature.