Regional Jet CL65; Undifferentiated or Other Model
Human-Machine Interface
Aircraft Equipment Problem Less Severe
Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Aircraft; Human Factors
The captain was the pilot flying and was climbing to FL340 when we received a DIFF PRESS master warning message. I looked at the cabin pressure data and the delta P read 8.6; but the cabin alt and rate were all normal indications. As a precaution we donned our crew O2 masks and the captain transferred the controls and the radios to myself; and he proceeded to run the QRH. I initiated a descent to 10000 coordinated with ATC and did not exceed 400 FPM in the descent because the cabin pressure was all normal. The captain completed the QRH and the message went away within 1 minute of starting the descent. We stopped our descent at FL250 with the QRH complete and all indications normal. A note in the QRH advised that when climbing above 30;000 feet at a VS of greater than 1500 FPM a master caution DIFF PRESS could occur. The company was advised and we continued to destination and climbed back to FL310.
In the CRJ-900 as we were about to level off at FL340 we received a DIFF PRESS master warning message. Cabin pressure was ok; but we put on the masks; and ran the QRH while simultaneously initiating a precautionary descent to 10;000. The message extinguished as we began our descent; which did not exceed 400 FPM; and the QRH stated to reduce vertical speed below 1500 FPM above 30;000 which had basically done. We stopped our descent at FL250; and made contact with dispatch. We climbed back to FL310 and proceeded without incident to our destination. Our vertical speed in the climb was greater than 1500 FPM above 30;000 in the CRJ-900 according to the note in the QRH.
CRJ900 flight crew receives a DIFF PRESS master warning message climbing to FL340. A descent is initiated before a note in the QRH is red indicating that a climb rate greater than 1500 FPM above 30;000 feet may cause the maximum differential pressure to be exceeded. With the differential pressure back to normal the flight is continued to destination at FL310.