On 18 March 2020, a Fokker 100 en-route to Port Moresby experienced a failure of the cabin pressurisation and air conditioning system due to a complete failure of the bleed air system. An emergency descent and a PAN were declared and a diversion to Madang completed. The Investigation noted unscheduled work on the bleed air system had occurred prior to the departure of the flight and that long running problems with this system had not been satisfactorily resolved until after the investigated occurrence when four malfunctioning components had finally been systematically identified and replaced.