A321
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; Flight Crew Took Evasive Action; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; Human Factors; Procedure
Require a pressure when replacing door sealsOur original flight was delayed by 3 hours due to a MX write up from the flight crew that brought the aircraft in. They noticed a loud noise coming from the rear of the plane while inflight. MX personnel found the rear cargo door seal needed to be replaced and did so. Once that was completed we boarded up the plane and took off for ZZZ. While climbing out through approximately FL280; the Captain and I notice the pressurization page pop up and the cabin alt flashing. The cabin altitude was climbing through 9000 at about 800-1000fpm. The Captain and I decided to don our oxygen masks and shortly after the ECAM message for high cabin ALT came on. At this point the Captain initiated an expedited decent and requested priority handling with Center and I ran the ECAM actions. The Captain descended and made a left hand turn back toward ZZZ1 away from the mountains. The flight attendants were notified by the Captain. Once the cabin altitude was back below 10;000 and the ECAM had extinguished we removed our masks and continued with ATC instructions with vectors to ILS 25L into ZZZ1. We ran all normal checklist and briefed the arrival/approach. Dispatch was notified via ACARS and operations via coms. The approach and landing was uneventful. The aircraft was under max weight and no damage had occurred. It was a normal landing with a couple emergency vehicles standing by. The oxygen masks in the cabin did not deploy and there were no injuries to any person. One flight attendant reported a headache and another used one of the aircraft's portable oxygen units. Neither of them wanted any medical assistance. While at the gate; MX personal looked at the cargo door. It was their belief that the new door seal was faulty.
First Officer reported loss of cabin pressure after maintenance had replaced a cargo door sill; resulting in an expedited descent and an air turnback.