An aircraft comprising: - a fuselage; - a main wing attached to the fuselage and configured to generate lift that acts on the aircraft; - an electric field sensor (20; 20a to 20d) configured to detect surface electric field intensities at four or more of mutually different positions on the aircraft; and - a flight controller, the flight controller comprising: - a storage that holds an electric field distribution table in which two or more samples are associated with two or more respective pieces of distribution data, the samples each corresponding to one of external electric fields having mutually different directions, the pieces of distribution data each including data on a distribution of reference surface electric field intensities at mutually different positions on an aircraft in a case where the aircraft receives the external electric field of corresponding one of the samples; and - a data extracting unit configured to extract one of the pieces of distribution data from the electric field distribution table on a basis of a result of detection performed by the electric field sensor (20; 20a to 20d); and - an electric field intensity calculator configured to calculate surface electric field intensities at the respective positions on a basis of the extracted piece of the distribution data; and characterized by the flight controller further comprising: - an attitude control unit configured to change an attitude of the aircraft on a basis of the calculated surface electric field intensities at the respective positions; wherein the surface electric field intensity refers to an intensity of an electric field generated on a surface of an airframe of the aircraft; wherein the data extracting unit is configured to cancel an offset component involved in the surface electric field intensities detected by the electric field sensor (20; 20a to 20d) and a ratio between any two of the surface electric field intensities detected by the electric field sensor (20; 20a to 20d) to extract one of the pieces of distribution data from the electric field distribution table, and wherein the electric field intensity calculator is configured to multiply the extracted piece of distribution data by a ratio between one of the detected surface electric field intensities and the reference surface electric field intensity at a corresponding position, of the positions, to calculate the surface electric field intensities at the respective positions. - a fuselage; - a main wing attached to the fuselage and configured to generate lift that acts on the aircraft; - an electric field sensor (20; 20a to 20d) configured to detect surface electric field intensities at four or more of mutually different positions on the aircraft; and - a flight controller, - a storage that holds an electric field distribution table in which two or more samples are associated with two or more respective pieces of distribution data, the samples each corresponding to one of external electric fields having mutually different directions, the pieces of distribution data each including data on a distribution of reference surface electric field intensities at mutually different positions on an aircraft in a case where the aircraft receives the external electric field of corresponding one of the samples; and - a data extracting unit configured to extract one of the pieces of distribution data from the electric field distribution table on a basis of a result of detection performed by the electric field sensor (20; 20a to 20d); and - an electric field intensity calculator configured to calculate surface electric field intensities at the respective positions on a basis of the extracted piece of the distribution data; and - an attitude control unit configured to change an attitude of the aircraft on a basis of the calculated surface electric field intensities at the respective positions; wherein the surface electric field intensity refers to an intensity of an electric field generated on a surface of an airframe of the aircraft; wherein the data extracting unit is configured to cancel an offset component involved in the surface electric field intensities detected by the electric field sensor (20; 20a to 20d) and a ratio between any two of the surface electric field intensities detected by the electric field sensor (20; 20a to 20d) to extract one of the pieces of distribution data from the electric field distribution table, and wherein the electric field intensity calculator is configured to multiply the extracted piece of distribution data by a ratio between one of the detected surface electric field intensities and the reference surface electric field intensity at a corresponding position, of the positions, to calculate the surface electric field intensities at the respective positions.