What happened
On September 22, 2015, an Embraer ERJ 145 (registration HB-IZP) was performing a commercial ferry flight from Geneva to Rome. While cruising at flight level 270, the flight crew noticed a rapid increase in cabin altitude, accompanied by a "CAB ALT HI" warning. As the cabin altitude exceeded 14,000 feet, the passenger oxygen system activated, prompting the crew to don their oxygen masks.
The pilots declared a MAYDAY and initiated an emergency descent to flight level 100. During the descent, the crew executed the rapid decompression checklist. Once the aircraft reached 14,000 feet, the crew removed their masks and stabilized the aircraft in cruise at the lower altitude. After canceling the distress call, the crew elected to continue the flight to the destination. There were no passengers on board during this repositioning flight, and the crew sustained no injuries.
The investigation
Following the incident, the aircraft underwent maintenance to identify the source of the pressure loss. Initial efforts focused on the pressurization control computer, which was replaced; however, a subsequent test flight revealed that the loss of pressure persisted.
Subsequent inspections of the fuselage were conducted to locate any structural breaches. Investigators discovered that the cargo door seal had become partially detached from its housing. Specifically, a section of the seal, measuring approximately 40 cm, had been forced out of its seat by the internal cabin pressure.
Findings
- The primary cause of the rapid decompression was a failure of the cargo door seal.
- The internal cabin pressure caused a 40 cm section of the seal to displace from its original position.
- The incident occurred during a ferry flight with no passengers on board.