The crash of British Airways Flight 38 (a Boeing 777-200ER) on January 17, 2008, was caused by ice crystals in the fuel system. During the long flight from Beijing to London, which passed over extremely cold regions in Siberia, small amounts of water naturally present in the jet fuel froze into "soft ice" or slush. As the plane made its final approach to Heathrow and the autothrottle commanded an increase in thrust, this slush was released from the fuel lines and moved forward, where it clogged the Fuel/Oil Heat Exchangers (FOHE) on both Rolls-Royce Trent 800 engines. This restricted the fuel flow, causing both engines to "roll back" and lose power just two miles from the runway. The pilots managed to glide the aircraft over obstacles, landing on the grass short of the runway. In 2026, this event is still cited as a landmark case that led to a global redesign of engine heat exchangers to prevent ice accumulation.