Falcon 20 flight crew reported pressurization control system malfunction inflight.
Synopsis
Falcon 20 flight crew reported pressurization control system malfunction inflight.
Narrative
We had filed FL360 as our final altitude to ZZZ departing from ZZZ1. On the ground we set out cabin altitude controller to maintain a cruise setting of FL370 as is standard on the FA20. We departed ZZZ1 and were instructed by the Center Controller to climb to an altitude above FL300 which we proceeded to do. As we were passing through approximately 27000ft I noticed and informed the Captain that the Cabin differential gauge was climbing into the red colored arc and read an approximate value of 8.7PSI the limitation for the aircraft's cabin. I then set the controller to a much higher altitude; approximately FL420; in the hope that this input on the controller would allow the cabin pressure differential to decrease at this same time we leveled the aircraft and informed ATC of our pressurization issue. Seeing that after a few moments there was no change to the Cabin Differential; we requested a descent and then subsequently [requested priority handling] with ATC who then cleared us to FL240. During the descent to FL240 and the level off; we saw no appreciable change in the cabin differential neither positive or negative and performed the emergency procedures as specified in the FA20 QRH to set our pressurization controller to manual and use a valve to manually control the cabin altitude.Upon completion of the QRH checklist we were able to quickly resolve the cabin over pressurization issue. Deeming that the issue was now non-critical and determining that we had adequate fuel to make it to our destination. We informed ATC our intentions to stay at FL240 for the duration of the flight to ZZZ and that we would like to cancel our emergency status and would advise for further assistance. The rest of the flight continued as normal with the exception of the abnormal use of the pressurization controller.
Second reporter narrative
Climbing thru Fl270 we noticed a higher than normal Cabin PSi and climbing at an abnormally high rate. We immediately requested a level off at 270 and then adjusted the cabin alt controller to a high cabin alt to reduce the pressure on the cabin. We then descended to 240 and referenced the QRH to determine next best steps. Followed QRH Procedure got the cabin under control cancelled the emergency and continued safely to destination.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.