Narrative:

After departing the gate we taxied to the de-ice area to have some residual ice removed from the aircraft. After the de-ice procedure was completed we performed the de-ice checklist (engines on-APU off); leaving the packs off until the two minute limitation was satisfied. Our departure was uneventful until reaching approximately 7000 feet when we received a 'display cool' cas message. Using the 'display cool' QRH we were only able to eliminate the message by using the standby fan after which we received a 'cabin altitude' cas message. Again we consulted the QRH and donned the oxygen masks; shortly after this we received a 'cabin altitude' warning message. We immediately requested a descent from 22;000 feet to 10;000 feet and declared an emergency. We were then rerouted back to our departure airport and then we contacted dispatch and informed the flight attendants and passengers of our intentions to return to the airport. We then performed the unpressurized landing QRH procedure when I reached to turn off the packs as instructed as per the QRH I discovered they were already off and that we had departed with them off as a result of the deicing procedure. I selected them on and the aircraft pressurization was restored. The maximum cabin altitude was 12;500 feet so I did not deploy the passenger oxygen masks. While I discovered our mistake I elected to continue to our departure airport since we were unsure of our fuel needed to continue the flight. Once on the ground I consulted with maintenance control and dispatch. The aircraft was refueled and we continued on. Suggestions: there were several mistakes that had I been more diligent could have prevented this incident. While we completed the deicing checklist as it is written we neglected to see that the packs were still off prior to takeoff when we performed the 'before takeoff' checklist. We should have seen the status of the packs when verifying the cas messages prior to departure. Another contributing mistake was made after takeoff. While I try to be in the habit of checking after I transfer the engine bleeds after takeoff I neglected to see that the packs were off and had I noticed their condition it would have been another opportunity to prevent this unfortunate incident. In the future I will be much more diligent in making sure the aircraft is configured properly prior to and after takeoff.

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Original NASA ASRS Text

Title: A CRJ-200 Captain experienced loss of cabin pressure after takeoff and soon realized the packs had never been turned on after pre-departure deicing.

Narrative: After departing the gate we taxied to the de-ice area to have some residual ice removed from the aircraft. After the de-ice procedure was completed we performed the de-ice checklist (engines on-APU off); leaving the packs off until the two minute limitation was satisfied. Our departure was uneventful until reaching approximately 7000 feet when we received a 'Display Cool' CAS message. Using the 'Display Cool' QRH we were only able to eliminate the message by using the Standby Fan after which we received a 'Cabin Altitude' CAS message. Again we consulted the QRH and donned the oxygen masks; shortly after this we received a 'Cabin Altitude' warning message. We immediately requested a descent from 22;000 feet to 10;000 feet and declared an emergency. We were then rerouted back to our departure airport and then we contacted Dispatch and informed the flight attendants and passengers of our intentions to return to the airport. We then performed the unpressurized landing QRH procedure when I reached to turn off the packs as instructed as per the QRH I discovered they were already off and that we had departed with them off as a result of the deicing procedure. I selected them on and the aircraft pressurization was restored. The maximum cabin altitude was 12;500 feet so I did not deploy the passenger oxygen masks. While I discovered our mistake I elected to continue to our departure airport since we were unsure of our fuel needed to continue the flight. Once on the ground I consulted with Maintenance Control and Dispatch. The aircraft was refueled and we continued on. Suggestions: There were several mistakes that had I been more diligent could have prevented this incident. While we completed the deicing checklist as it is written we neglected to see that the packs were still off prior to takeoff when we performed the 'Before Takeoff' checklist. We should have seen the status of the packs when verifying the CAS messages prior to departure. Another contributing mistake was made after takeoff. While I try to be in the habit of checking after I transfer the engine bleeds after takeoff I neglected to see that the packs were off and had I noticed their condition it would have been another opportunity to prevent this unfortunate incident. In the future I will be much more diligent in making sure the aircraft is configured properly prior to and after takeoff.

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.