A crj-50 flight crew initiated an emergency descent when multiple pneumatic system anomalies resulte...

Narrative:

Climbing through FL270; we received an anti-duct warning message. Since I was the flying pilot; I continued flying and handled the radios while the captain ran the QRH. Upon completion of the QRH; he contacted dispatch to begin making plans for alternate airport since icing conditions were in the area. While I continued the climb; we received a cabin altitude caution message. I referred to the ecs page and noticed the cabin rapidly climbing through 8;700 ft. I requested an immediate descent to 10;000 ft and upon conferring with captain; we donned our oxygen masks and began an emergency descent.while in the descent; we then received a cabin warning message. To the best of my knowledge; I recall seeing the cabin climb to around 13;500 ft. Talking with ATC; we decided our best course of action was to land; since we did not have wing anti-ice capabilities and we could stay out of icing conditions. After the captain talked with the flight attendant and passengers and advised them of the situation; we made an eventful landing at our alternate.

Original NASA ASRS Text

Title: A CRJ-50 flight crew initiated an emergency descent when multiple pneumatic system anomalies resulted in the loss of cabin pressurization. The diverted to a nearby airport due to the loss of all pneumatic anti-ice functions.

Narrative: Climbing through FL270; we received an anti-duct warning message. Since I was the flying pilot; I continued flying and handled the radios while the Captain ran the QRH. Upon completion of the QRH; he contacted Dispatch to begin making plans for alternate airport since icing conditions were in the area. While I continued the climb; we received a cabin altitude caution message. I referred to the ECS page and noticed the cabin rapidly climbing through 8;700 FT. I requested an immediate descent to 10;000 FT and upon conferring with Captain; we donned our oxygen masks and began an emergency descent.While in the descent; we then received a cabin warning message. To the best of my knowledge; I recall seeing the cabin climb to around 13;500 FT. Talking with ATC; we decided our best course of action was to land; since we did not have wing anti-ice capabilities and we could stay out of icing conditions. After the Captain talked with the Flight Attendant and passengers and advised them of the situation; we made an eventful landing at our alternate.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	921554
Time
Date	201011
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	Regional Jet CL65 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Pneumatic System
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Commercial
Experience	Flight Crew Last 90 Days 210 Flight Crew Total 8500
Events
Anomaly	Aircraft Equipment Problem Critical

A crj-50 flight crew initiated an emergency descent when multiple pneumatic system anomalies resulted in the loss of cabin pressurization. The diverted to a nearby airport due to the loss of all pneumatic anti-ice functions.