(1) Tests upon a balloon of the type for which certification is requested or by calculations based on, and equal in accuracy to, the results of testing; and
(2) Systematic investigation of each weight if compliance cannot be reasonably inferred from the weights investigated.
(b) Except as provided in §31.17(b), allowable weight tolerances during flight testing are +5 percent and −10 percent.
[Amdt. 31–4, 45 FR 60179, Sept. 11, 1980]