What happened
On January 5, 2015, a Bombardier DHC-8-400 operated by Eurolot SA was performing a climb through approximately 1,500 feet within the Warsaw (EPWA) TMA when the crew experienced an unnaturally rapid change in cabin pressure. Upon passing the transition altitude, the flight crew verified the instruments, which confirmed a pressurization failure; the cabin altimeter indicated a rising altitude, and the variometer showed a climb rate exceeding 3,000 feet per minute.
During this period, cabin crew reported unusual noise originating from the rear section of the fuselage. In response to the depressurization, the pilot leveled off the aircraft at FL080 and notified Air Traffic Control of the pressurization issue. The crew performed the "CABIN PRESS" checklist, though they noted that the Crew Warning Panel had failed to activate. Unable to regain control of the cabin pressure, the captain decided to return to the departure airport in Warsaw. The aircraft landed without further incident, and no emergency was declared during the flight.
The investigation
The investigation focused on the source of the pressure change and the unusual noise reported by the crew. Investigators examined the rear cargo compartment and identified that a blow-up panel on the rear bulkhead had dislodged. The investigation also assessed the integrity of the cargo door and the cabin pressure control systems.
Findings
- The primary cause of the incident was a leak in the rear cargo doors.
- The rapid pressure change and the noise heard by the crew were caused by the displacement of a blow-up panel on the rear bulkhead of the cargo compartment.
- The probable cause of the depressurization was the improper closing of the cargo door.