View Full Version : Pressurization 737 Takeoff

15th Mar 2008, 15:40

assuming the outflow valve is stuck in closed pos, or nearly closed pos. going airborne and the auto fail light comes on. what happend?pressure inside the aircraft is much greater than outside?what to do? did you encounter such situation?



15th Mar 2008, 15:59
hi there,

well u also have a standby mode and if that also fails there is the posibility to control the position of the outflow valve ( and therefore regulate pressure) via a manual AC or DC motor.. but theoretically speaking if it did get stuck in the closed position then u also have the option of turning on and off the pack to increase and decrease the amount of air being pumped into the cabin ( not sure if this is recommended) plus u have a pressure relief valve which will stop the differential pressure from exceeding 8.65psi so i don't thing u will be in too much trouble if what u described happened

15th Mar 2008, 20:29
AC motors for the outflow valve are only available on airplanes with CPCS installed, DCPCS (NG and newer classics) installations only use DC motors.