An aircraft includes: a fairing which covers a lower part of a fuselage having a main landing gear bay (MLG bay), and defines a ventilation cavity communicating with the MLG bay between the fairing and the fuselage; and a heat removal system which removes heat generated from the MLG inside the MLG bay to the outside of the MLG bay by suctioning/discharging air through an inlet port and an outlet port leading from the ventilation cavity or the MLG bay to external air. The fairing defines a wheel opening through which a wheel of the MLG enters and exits, and defines a ventilation port, which functions as one of the inlet and outlet ports, between the fairing and an outer peripheral part of the wheel exposed from the wheel opening to the lower side of the MLG bay when the MLG is retracted.