Luckily for us, NASA already performed an ash cloud test on an airliner a full decade ago, albeit unintentionally. In February of 2000, a NASA DC-8 bound for Sweden flew right through an ash plume produced by Icelandic volcano Mt. Hekla. The flight crew couldn't see the plume, and in a stroke of good fortune they landed their plane at their destination without incident. In fact, no visible damage was detected upon arrival, but a closer inspection turned up some harrowing clues to just how devastating volcanic ash can be on an airplane in flight.