What happened
On June 24, 2007, at approximately 17:40 local time, a BAe 146-200 operating for a German carrier was climbing through flight level 240 during a scheduled flight from Frankfurt/Main to Bremen. During the cruise phase, the aircraft experienced a sudden loss of cabin pressure.
In response to the depressurization, the crew declared an emergency and initiated an emergency descent to flight level 100. To manage the altitude change, the crew utilized supplemental oxygen masks. During the descent, one individual experienced a severe anxiety attack and required medical attention. The flight was subsequently diverted to Paderborn-Lippstadt, where the aircraft landed safely. There were no injuries to the aircraft or crew, aside from one person who required medical care for an anxiety-related condition.
The investigation
The BFU conducted a technical inspection of the aircraft following the incident. The investigation focused on the mechanical systems responsible for maintaining cabin pressure and the integrity of the aircraft's pressure vessel.
Findings
Technical examination of the aircraft revealed that water had accumulated within the control lines of the rear outflow valve. This moisture interfered with the operation of the valve's control mechanism, which directly caused the loss of cabin pressure during flight.