Yes it was a British Airways 747-236B, registration G-BDXH, the 'City of Edinburgh' (as it was called at the time), was on it's way to Perth (I think, not sure) and was flying over Indonesia when ash from a nearby volcano caused all 4 engines to cut out.
The volcanic ash was so bad that the flight deck window was completely covered, and the flight crew therefore had terrible visibility problems.
I remember reading a book on the subject, and one page showed a photograph of one of the strobe light covers, it was completely covered with ash, as though someone had sprayed it.
The aircraft in question is still in operation with British Airways (now called 'City of Elgin'), almost 20 years after the incident.
I love it when a plan comes together