Pressure relief panel for aircraft powerplant

A gas turbine powerplant having an outer wall, and a pressure relief panel disposed on said outer wall, said pressure relief panel comprising:

• a frangible diaphragm within an enclosure defined by walls, the first one of the walls including an apertured area which is overlaid by the frangible diaphragm so that in operation the diaphragm is exposed to pressures on both sides of the wall but no flow passes through the wall, the diaphragm being adapted to break up when the pressure difference across the wall exceeds a predetermined minimum, a second one of the walls forming a cover over the diaphragm and adapted to form a smooth continuation of the powerplant outer surface, said second wall being apertured to allow exposure of the interior of the enclosure to the external pressure, the apertures in the second wall being sized so that the total area thereof is sufficient to allow excape of the excess fluid therethrough after break up of the diaphragm, but the individual areas thereof are such as to prevent escape from the enclosure of parts of the diaphragm of such size as to be a potential danger to the aircraft or other powerplants.