The AGAIR aircraft VH-HPY pressurisation system could not reliably attain the required cabin altitude during flight due to a known, long-term, unresolved intermittent defect. AGAIR management personnel were aware of the defect and, through a combination of inaction, encouragement and, in some instances direct involvement, permitted the aircraft to continue operations at an excessive cabin altitude.
VH-HPY was destroyed in the accident, so the safety issue specific to this aircraft no longer exists.