"Ladies and gentlemen, this is your captain...
was no thunderstorm in the region, however. It appeared that the airliner, flying at an altitude of 11,000 meters, entered a cloud of volcanic ash suddenly spewed by the Javan volcano Galunggung.Fumes began building in the passenger cabin. Knowing nothing of the volcano, the general conclusion was that it was cigarette smoking - in those days smoking was allowed on aircraft. Soon, however, the fumes thickened, setting off an alarm in the cabin. Crew members set about searching for the cause, but naturally failed to find any.
Meanwhile, many passengers looking out the aircraft windows spotted an unusually brilliant glow on the body surface and particularly on the engines as though each carried a lamp illuminating the way ahead through compressor blades, which created a stroboscopic effect. This glow came from electrified dust particles that had settled on the surface of engine nacelles and on the compressor blades.