FAA Federal Aviation Regulations (FARS, 14 CFR)

(a) The empty weight and corresponding center of gravity must be determined by weighing the rotorcraft without the crew and payload, but with --

(1) Fixed ballast;

(2) Unusable fuel; and

(3) Full operating fluids, including --

(i) Oil;

(ii) Hydraulic fluid; and

(iii) Other fluids required for normal operation of roto-craft systems, except water intended for injection in the engines.

(b) The condition of the rotorcraft at the time of determining empty weight must be one that is well defined and can be easily repeated, particularly with respect to the weights of fuel, oil, coolant, and installed equipment. (Secs. 313(a), 601, 603, 604, and 605 of the Federal Aviation Act of 1958 (49 U.S.C. 1354(a), 1421, 1423, 1424, and 1425); and sec. 6(c) of the Dept. of Transportation Act (49 U.S.C. 1655(c)))

[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-14, 43 FR 2324, Jan. 16, 1978]