Date: 202012
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: A300
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Cruise
ATC / advisory: Center ZZZ
Aircraft component: Pressurization System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Time Pressure; Troubleshooting
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Diverted; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Climbing to enroute altitude of 33;000 ft. MSL; received an advisory of malfunctioning outflow valve. Eventually; after being unable to establish control of cabin pressure altitude; failure of both automatic pressure controllers and no control over manual control; we requested priority handling and ATC cleared us to a lower altitude where we were able to maintain a safe cabin altitude. Diverted into ZZZ2. ZZZ2 Maintenance discovered on inspection that the aircraft fwd outflow valve had become obstructed from loose insulation material and prevented its operation.


Second narrative: We had reached cruise at FL330 enroute from ZZZ-ZZZ1. The ECAM gave us an advisory that the cabin altitude was above normal. I was the PF (Pilot Flying). The Captain worked the problem. We noticed that the cabin altitude was approaching 8;700 ft. and had a trend to climb higher at 50-200 fpm. Looking at the pressurization schematic; we could see that the forward outflow valve was full open and should have been full closed. The aft outflow valve was normal at full closed. We referenced the QRH for all actions. The Captain switched the pressure controller to manual mode and attempted to close the forward outflow valve but it would not close. We discussed diverting to ZZZ2 and requesting priority handling. At a certain point; the ECAM indicated that both auto pressure controllers failed. As we could not control the cabin altitude in any mode; we requested priority handling and asked for a lower altitude. Initially; ATC cleared us to FL 240 and then later 16;000 ft. while we were descending. We were able to maintain terrain clearance and stay above the weather. We were cleared direct to the ZZZ2 airport and set up for an ILS to Runway XXR. We encountered moderate turbulence while we were at 320 kts. This caused the airplane to momentarily overspeed to about 335-340 kts. I slowed the airplane and we continued our descent. We flew an uneventful approach to Runway XXR and landed safely and taxied to parking. Upon inspection; we were told Maintenance discovered a piece of insulation stuck in the forward outflow valve the prevented it from closing. We later continued on with a separate flight to ZZZ1.


Synopsis: A300 flight crew reported a pressurization problem that resulted in a diversion.