Abstract: An aircraft such as a gyroplane has a thrust propeller, a tail unit, a fuselage, and a keel tube that links the tail unit to the fuselage. The keel tube has a structure that reduces sound. The sound-reducing structure has a flow line-shape, is arranged at least partly below the thrust propeller, and extends from the keel tube in directions normal a vertical longitudinal plane of the gyroplane. The sound-reducing structure may extend asymmetrically from the keel tube and may be located along the longitudinal axis of the gyroplane on the keel tube within an angle between 10 degrees forward and 30 degrees rearward a vertical line extending to the keel tube from the intersection of the thrust propeller rotational axis and the thrust propeller rotational plane. The sound-reducing structure may also contain a sound-absorbent material or may comprise a hollow body with several openings.

Abstract: The invention relates to an aircraft with a thrust propeller (18), a tail unit (20) and a connection (22) by means of which the tail unit (20) is fastened. According to the invention, it is provided that the connection (22) has a sound-absorbing structure (24).