Dirk Barreveld 
Air Crash Investigations – Loss of Cargo Door – The Near Crash of United Airlines Flight 811 [EPUB ebook] 

On February 24, 1989, United Airlines flight 811, a Boeing 747-122, lost a cargo door as it was climbing between 22, 000 and 23, 000 feet after taking off from Honolulu, Hawaii, en route to Sydney, Australia with 355 persons aboard. As a result of the incident nine of the passengers were ejected from the airplane and lost at sea. The cargo door was recovered in two pieces from the ocean floor at a depth of 14, 200 feet on September 26 and October 1, 1990. The probable cause of this accident was a faulty switch or wiring in the door control system. Contributing to the cause of the accident was a deficiency in the design of the cargo door locking mechanisms. Also contributing to the accident was a lack of timely corrective actions by Boeing and the FAA following a 1987 cargo door opening incident on a Pan Am B-747.