When the National Transportation Safety Board announces the probable cause of an accident, it often makes use of certain stock phrases. One of the most common is: “loss of control for undetermined reasons.”
Unlike “controlled flight into terrain,” which can often be traced to an incorrectly selected radio frequency or a sectional chart left behind, loss of control for undetermined reasons remains mysterious. These are not the loss-of-control accidents that result from icing encounters or from a non-instrument-rated pilot flying into IMC; in those cases, reasons can at least be plausibly guessed. Undetermined reasons really are undetermined.
