Probable Cause
The NTSB reopened the UAL 585 case after the crash of another B-737, USAir Flight 427, which occurred three-and-a-half years later. It was eventually determined that both crashes were the result of a sudden malfunction of the rudder power control unit. The pilots lost control of the airplane because "The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit servo valve secondary slide to the servo valve housing offset from its neutral position and overtravel of the primary slide."
Read more about this topic: United Airlines Flight 585
Famous quotes containing the word probable:
“It makes me hate accepting things that are probable when they are held up before me as infallibly true. I prefer these words which tone down and modify the hastiness of our propositions: “Perhaps, In some sort, Some, They say, I think,” and the like.”
—Michel de Montaigne (1533–1592)
“It is the mark of an educated man to look for precision in each class of things just so far as the nature of the subject admits; it is evidently equally foolish to accept probable reasoning from a mathematician and to demand from a rhetorician demonstrative proofs.”
—Aristotle (384–323 B.C.)