Aircraft Decompression with Installed Cockpit Security Door

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A zero-dimensional model of cockpit and cabin decompression with cockpit security door is presented. The hinged panels in the security door were modeled to account for the pressure-equalization dynamics in the case of cockpit decompression. A comprehensive isentropic and isothermal theoretical analysis is presented with many closed-form and asymptotic solutions. New analytical estimates for the total decompression time and the pressure half-time were derived. The simulations for typical corporate and large-transport-category airplanes with different cabin geometries, discharge coefficients, rupture cross-sectional areas, pressure altitudes, and cabin altitudes have been obtained. The case in which the cockpit depressurizes first and its effect on the cabin decompression and on the security door integrity has been extensively studied. The recently required cockpit doors may be hazardous for flight crew in the case cockpit depressurizes first and other venting and blowout panels malfunction or are too slow to respond. The resulting pressure differential between the cockpit and the cabin can create instantaneous forces in excess of 80 kN on the cockpit security door. In addition, this puts the crew in danger due to explosive decompression on the time scale of 100 ms and increases the possibility of the security door being blown out of the frame.


Aviation, Mechanical and Civil Engineering

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Journal of Aircraft