Emb-145 flight crew reported being unable to maintain cabin pressurization due to one air conditioni...

Attributes
ACN	1593295
Time
Date	201811
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	EMB ERJ 145 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning and Pressurization Pack
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Inflight Event / Encounter Weather / Turbulence

Narrative:

Flt level 240 we recognized we were in and out of icing conditions with one pack MEL'd. We noticed while flying that the anti-ice system came on. Then the cabin started to rise. We descended to FL220 in order to get out of ice conditions. We donned our masks. That wasn't low enough so we continued to 18000 ft but we received a master cabin warning. As we descended the cabin pressure was still rising. The captain called the flight attendant and we continued down to 11000 ft to stabilize the cabin. Still in ice we further went down to 9000 ft. We worked on the diversion items and diverted to ZZZ. No emergency was declared.our crew communications was great. We constantly were sharing for a shared mental model. The captain had everything seem seamless and did a fantastic job!

Original NASA ASRS Text

Title: EMB-145 flight crew reported being unable to maintain cabin pressurization due to one air conditioning pack being inoperative and the anti-ice system in use.

Narrative: Flt level 240 we recognized we were in and out of icing conditions with one pack MEL'd. We noticed while flying that the anti-ice system came on. Then the cabin started to rise. We descended to FL220 in order to get out of ice conditions. We donned our masks. That wasn't low enough so we continued to 18000 ft but we received a Master Cabin Warning. As we descended the cabin pressure was still rising. The Captain called the Flight Attendant and we continued down to 11000 ft to stabilize the cabin. Still in ice we further went down to 9000 ft. We worked on the diversion items and diverted to ZZZ. No emergency was declared.Our crew communications was great. We constantly were sharing for a shared mental model. The Captain had everything seem seamless and did a fantastic job!

Data retrieved from NASA's ASRS site 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.

Emb-145 flight crew reported being unable to maintain cabin pressurization due to one air conditioning pack being inoperative and the anti-ice system in use.