Citationjet (C525/C526) - CJ I / II / III / IV
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 150; Flight Crew Total 3000; Flight Crew Type 30
Human-Machine Interface
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Other / Unknown
Flight Crew Overcame Equipment Problem
Human Factors; Aircraft
On climb out during checklist passing FL180 I (pilot not flying) noticed the pressurization was not working correctly. I informed the Captain (pilot flying) of the problem and we both agreed the cabin was climbing rapidly and was nearing 10;000 FT cabin altitude. I immediately asked ATC for a level off (at this time we were approaching FL200) followed by requesting a descent to 10;000 FT. ATC issued us a hand off in response and I told them we needed an emergency descent to 10;000 FT immediately. Controller asked us nature of problem to which I told them it was a pressurization issue. They cleared us to 10;000 FT and we performed an emergency descent. No emergency was declared and we confirmed with ATC that they did not declare one for us nor [gave us] any indication of one being filed. At 10;000 FT cabin became controllable and everything worked fine. We elected to continue on flight plan and step climb slowly monitoring system. Maintenance inspected the plane and found no discrepancies.
CE525 First Officer experiences pressurization anomalies climbing through FL180 and the climb is stopped and a descent is initiated with ATC concurrence. The pressurization seems to function normally at 10;000 FT and the crew climbs to planned altitude and continues to destination. Maintenance can find no discrepancies.