An aircraft 1 with a spiral inducing assembly 2 which is capable of inducing the aircraft to travel in a continuous spiralling motion without the aircraft rolling. A counting module activated during successive time periods calculates a differential numerical value representing the algebraic difference between the two numbers of bits of the binary signal that respectively have the second binary value and the first binary value. The arrangement direction of the nozzle holes crosses the direction, which is perpendicular to the scanning direction, at a predetermined angle when the spacer dispersion solution obtained by dispersing the spacers in the solvent is discharged from the plurality of nozzle holes while the nozzle head is scanned along the predetermined scanning direction.