From Australian Viewer- Please ask Miles O.Brien to investigate Boeing 747 United Airlines flight 811 from Honolulu to Australia1989 which lost 9 People when a cargo door was ripped from floor of Business Class 20 mins out of Hawaii. Ask also about pre flight notification to pilot via message from maintenance officer re signal from rear door closure denoted fact that had not been closed correctly. First officer investigated prior to take off and aftr3er several minutes of shaking and banging came back to thank holidaying maintenance engineer for the alert. This was not the door which landed in the pacific. Aircraft was on last flight before being returnee from service. This happened EARLY 1989 so WHAT IS NEW?