Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface
Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Landed in Emergency Condition; General Declared Emergency
Aircraft
Upon arriving at the airplane in the morning; the Flight Attendant reported that the vents were blowing hot air. Unable to control the temperature in automatic or manual mode; we consulted with Maintenance; who deferred the right pack and cabin temperature controller. For our departure; we followed the procedure outlined in the MEL book for operations with the left pack only. During climb; while passing through FL240; the Captain and I noticed the cabin altitude suddenly rising rapidly and the delta P dropping; and we felt a severe pressure change in our ears. Our left pack had tripped offline. We immediately completed the Emergency Descent Immediate Action items and I began following the QRH procedures. We also declared an emergency and began a rapid descent to 10;000 FT. Upon reaching a safe altitude; I briefed the Flight Attendant and the Captain explained the situation very briefly to the passengers. Very shortly into the event; we received an amber L PACK HI TEMP CAS message. We completed the QRH for the emergency descent and then began working the L PACK HI TEMP QRH. During this QRH procedure upon recycling the pack; we noticed a burning smell; we immediately switched off the pack and picked up the speed to the airport. From this point on; a normal Descent Checklist; briefing; and normal landing occurred; and the fire trucks accompanied us to a normal deplane at the gate.
After being dispatched with one air conditioning pack deferred a CRJ-200 flight crew suffered the loss of the remaining pack as they climbed through FL240.