Abstract: An apparatus warns of differential pressure during the opening of a pressure-loaded door that closes an opening in an aircraft fuselage. An air guide passage extends from the side with higher pressure to the side with lower pressure. The air guide passage is closeable by a valve that is controllable with a control lever operatively Connected to a door opening mechanism. When there is a differential pressure between the two sides, upon opening of the valve the apparatus produces an acoustic signal as a differential pressure indication that is independent of a supply system and serves as a warning signal for the operator of the aircraft door.

Abstract: In an apparatus for warning of differential pressure during the opening of a pressure-loaded closure device (1) of an opening in the aircraft fuselage by means of an opening mechanism (4; 100; 105), the invention exists in that an air guide passage is provided from the side with higher pressure (passenger cabin P) to the side with lower pressure (outside environment A). The air guide passage is closeable by a valve (5; 209), whereby it is controllable with a control lever (4; 208) placed in operative connection with the door opening mechanism, and produces an acoustic signal upon opening of the valve (5; 209) and an existing differential pressure. With such a warning apparatus, a differential pressure indication independent of a supply system is provided and serves as a warning signal for the operator of an aircraft door. Thereby, the differential pressure indication is directly coupled to the action of the operator.