Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 98; Flight Crew Total 8803
Fatigue
Aircraft Equipment Problem Critical
Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification
Aircraft
We had an early morning showtime in ZZZ of XA:45am. There was one pack inoperative on our aircraft. There was previous overnight snow; low visibility; deice required; involved mountain airport departure and EO (Engine Out) procedure; so there was added workload for departure. On climbout through FL220; the remaining pack did not maintain pressurization; the cabin was climbing slowly through 10;000 ft. We slowed the climb; then eventually descended to get the cabin altitude lower; but still could not control the cabin pressurization. The Captain [requested priority handling] with ATC; and we made an emergency descent and diverted into ZZZ1. After almost 5 hours on the ground; maintenance fixed the aircraft and we departed to ZZZ2. We received notices from the crew desk that they wanted to re-assign us to fly another flight upon arrival in ZZZ2. This would have taken us within an hour of our [duty time]; and would have extended our duty day to over 12+ hours. I declined the re-assignment and declared fatigued upon arrival in ZZZ2.
A319 First Officer reported diverting due to the aircraft's inability to maintain cabin pressure.