§25.29 Empty weight and corresponding center of gravity.

(a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with-- (1) Fixed ballast; (2) Unusable fuel determined under Sec. 25.959; and (3) Full operating fluids, including-- (i) Oil; (ii) Hydraulic fluid; and [(iii) Other fluids required for normal operation of airplane systems, except potable water, lavatory precharge water, and fluids intended for injection in the engine.] (b) The condition of the airplane at the time of determining empty weight must be one that is well defined and can be easily repeated.