In order to assist the post-emergency investigation, GT re-enacted the dramatic sequence of events in the Cessna Piper Warrior simulator. “This confirms to me that a pressurisation failure passing about 600’ into rotation is the most likely cause of this near-disaster. I anticipate that the Transport Safety Bureau will be looking very closely at cabin pressurisation valve maintenance records. It would not surprise me if CASA issued a directive requiring an urgent inspection of all of these valves on the Cessna Piper Warrior.”