An ERJ190 with one Auto Pressurization Control channel MEL'ed; had both the second Auto and Manual pressurization controls fail as the descent from FL370 was begun. An emergency was declared; a descent begun and cabin passenger masks dropped descending through 18;000.
Synopsis
An ERJ190 with one Auto Pressurization Control channel MEL'ed; had both the second Auto and Manual pressurization controls fail as the descent from FL370 was begun. An emergency was declared; a descent begun and cabin passenger masks dropped descending through 18;000.
Narrative
At FL370 given clearance to cross an arrival fix at FL250 and 300 KTS on the descent into our destination. Shortly after the aircraft began the descent all auto and manual pressure control systems indicated a failure. The cabin began climbing. The flight deck crew donned oxygen; declared an emergency with the Center and requested descent to 10;000 MSL. On the descent the cabin altitude climbed above 14;500 MSL. We were given clearance direct to an arrival intersection at 8;000 MSL. We continued unpressurized to a landing. There were no injuries reported. Customer Service personnel met the aircraft upon arrival. There was no jetway operator at the gate so operations were notified and we were delayed in deplaning. One auto pressure control channel was inoperative and on MEL. There were no indications of anything other then normal until additional failures accrued. Cabin was at 8;000 MSL and the pressure differential was 8.3 PSI at FL370. It did seem that once the thrust was reduced for the descent; the failures occurred. After inspection of the cabin I noticed that several oxygen masks were deployed; but not used by the passengers. This flight was an initial operation flight for the First Office in training; I appreciated his high level of performance as he definitely met and exceeded the standard.
Second reporter narrative
As the aircraft approached the top of descent and throttles retarded we received a 'pressurization auto fail' caution message. Almost at the same instant; we received a second caution 'pressurization manual fail'. Looking at the pressurization information I saw the cabin climbing. The Captain said 'we may have to start down now'. The Captain took control of the aircraft and said 'put on your oxygen mask' and called for the immediate action items. I ran through the immediate action items; declared an emergency with ATC; asked for a lower altitude and then ran the QRH procedure for 'cabin high/rapid depressurization'. Shortly after descent we received a 'cabin altitude high' warning. At some point below 18;000 FT the cabin hit 14;500 FT and the masks deployed in the cabin. Upon reaching 10;000 FT; I called the Flight Attendants and obtained a status report; asking if everyone was OK and if there were any injuries. The Flight Attendants said everyone was fine. We decided to continue without further incident.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.