Aircraft Fuel Systems (1) The fuel jettison valve must be designed to allow flight personnel to close the valve during any part of the jettisoning operation. (2) During the fuel jettisoning operation, the fuel must discharge clear of any part of the airplane. Regarding the above statements, a. both No. 1 and No. 2 are true. b. only No. 2 is true. c. neither No. 1 nor No. 2 is true.