What happened
On 26 July 2017, a Beech 200 Super Kingair, registration G-KVIP, was operating a non-revenue commercial flight from Exeter to Faro, Portugal. While climbing through FL275, having been cleared to FL280, the aircraft experienced a loss of cabin pressure, triggering the altitude warning on the flight deck.
As a result of the depressurisation, the passenger oxygen masks deployed. The two passengers on board were able to secure their masks without difficulty. However, the pilot encountered significant trouble donning his own oxygen mask because the equipment had become entangled with various items located behind the pilot's seat.
Following the incident, the pilot notified Air Traffic Control and initiated an emergency descent to FL100. The flight was diverted back to Exeter, which serves as the operator's maintenance base. The aircraft landed safely on Runway 26 without further incident. Upon engine shutdown, the pilot reported feeling unwell, though he attributed this sensation to the recent depressurisation event.
The investigation
The investigation focused on identifying the source of the pressure loss and the cause of the pilot's difficulty with the oxygen equipment. Maintenance inspections conducted by the operator's maintenance organisation identified two distinct leaks contributing to the loss of cabin pressure: a faulty outflow valve and a leaking landing gear seal. Both components were subsequently replaced, and a successful air test confirmed the integrity of the pressurisation system.
Findings
- The loss of cabin pressure was caused by leaks from the outflow valve and a landing gear seal.
- The pilot's ability to use the oxygen mask was hindered by physical obstructions behind the seat.
- No injuries were sustained by the crew or passengers, and there was no damage to the aircraft.