Volcanic ash clouds; a continuing threat to international aviation

There was no warning. The British Airqays Boeing 747 was making its usual flight from Kuala Lumpur to Perth, Asutralia, that nihgt, late in June 1982. Altitude:12,000 metres (37,000 feet). Time about 23:00 UTC.

Suddenly, an acrid odour began to pervade the aircraft, an eerie bluish glow lit up the edges of the wings, and in the cockpit the familiar hum of static started to break up the high-frequency communications. Then it happened.