single-seat aircraft; single-seater
Refers to an aircraft designed for one pilot or occupant. Used in aviation contexts.
He performed aerobatics in a single-seat aircraft.
複座機 means a two-seat aircraft, contrasting with 単座機's single-seat design.
Standard kanji spelling using 座 (seat).
Variant using 坐, an older form of 座. Less common but still encountered.
Compound of 単 (single) + 座 (seat) + 機 (aircraft).