The invention pertains to a relief valve (10) for being arranged on an opening (10) of a fuselage shell of an aircraft, wherein the opening (10) has a front opening edge (9a) and a rear opening edge (9a), and wherein the relief valve (10) features: a cover (13) that is arranged on the fuselage shell by means of an opening and closing device in order to open and close the opening (10) of the fuselage shell, and a prestressing device for prestressing the cover (13) into an initial position, wherein a guide plate (23) is arranged on the cover (13) by means of a mounting device (20), wherein the guide plate is spaced apart from the cover (13) and extends along the cover (13), and wherein the invention furthermore pertains to a fuselage part with such a relief valve (10) for being installed into an aircraft fuselage with a fuselage shell and a plurality of fuselage frames arranged on the inside of the fuselage shell, as well as to an aircraft fuselage with such a fuselage part.