AAIB investigation to Piaggio P 180 Avanti II, D-IPPY
Depressurisation, near Southend-on-Sea, Essex, 19 September 2020.
Summary:
The aircraft departed London Luton Airport en route to Riviera Airport, Albenga, Italy, without event. During the climb passing FL220, the commander, who was PF, heard a dull sound that he believed was an outflow valve opening in the rear of the aircraft. Upon observing the cabin altitude, it indicated a climb of about 4,000 ft/min. The PM informed ATC that they were going to level off at FL230 in order to monitor the cabin altitude. As the cabin altitude continued to climb, and was approaching 10,000 ft, the commander manually deployed the passenger’s oxygen masks and the crew donned theirs.
A PAN was declared and an emergency descent to FL100 requested to ATC. The aircraft was initially cleared to FL200, due to traffic below, but was soon re-cleared to FL100. The descent was continued and the appropriate checklist completed. The aircraft diverted to London Biggin Hill Airport where it landed, with the RFFS in attendance, without further event. There were no injuries.
The engineering investigation discovered a clamp connecting a hose to the Environmental Control System had become lose, possibly as a result of vibration, leading to a loss of cabin pressure. After rectification the aircraft was released to service.
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