There were two incidents in this country with the HS748 - that I know of - where w/m tank contamination led to loss of the aircraft. The first was in Churchill MB where the w/m tanks had been filled with Jet B. The aircraft got airborne, but was forced landed on the river just off the end of the runway. In the second, the aircraft was serviced from a drum containg scrap liquid, containing among other goodies, MEK and acetone. On the first wet take-off attempt, the right engine sh#t itself on the take-off roll and the aircraft burned.