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British Airways Flight 38 (call sign ''Speedbird 38'') is a scheduled flight operated by British Airways from Beijing Capital International Airport to London Heathrow Airport. On 17 January 2008, the Boeing 777 used for the flight, having completed the trip, crash landed just short of the runway at its destination.〔〔 There were no fatalities but 47 people sustained injuries; one serious.〔 The 150-tonne aircraft was the first Boeing 777-200ER to be written off in the model's history,〔 〕〔 〕 and the first hull loss of any Boeing 777. Ice crystals in the fuel were blamed as the cause of the accident, clogging the fuel-oil heat exchanger (FOHE) of each engine. This restricted fuel flow to the engines when thrust was demanded during the final approach to Heathrow. Boeing identified the problem as specific to the Rolls-Royce engine fuel-oil heat exchangers, and Rolls-Royce subsequently developed a modification to its FOHE; the European Aviation Safety Agency (EASA) mandated that all affected aircraft were to be fitted with the modification before 1 January 2011.〔〔 (【引用サイトリンク】 Boeing links Heathrow, Atlanta Trent 895 engine rollbacks )〕 Boeing 777 aircraft powered by General Electric or Pratt & Whitney engines were not affected by the problem.〔 ==Accident== The aircraft used for the flight was Boeing 777-236ER (manufacturer's serial number 30314, line number 342), powered by two Rolls-Royce Trent 895-17 engines. The aircraft first flew on 18 May 2001 and was delivered to British Airways on 31 May 2001.〔http://www.planespotters.net/Production_List/Boeing/777/30314,G-YMMM-British-Airways.php〕 It had a seating capacity for 233 passengers.〔AAIB final report, section 1.6.5.1 (page 12) "Cabin Layout"〕 Flight 38's route took it over Mongolia, Siberia and Scandinavia, at an altitude which varied between 34,800 and 40,000 ft (FL348–400, between 10,600 and 12,200 m), and in temperatures between −65 and −74 °C.〔AAIB final report, section 1.7.2 (pages 33–34)〕 Aware of the cold conditions outside, the crew monitored the temperature of the fuel, with the intention of descending to a lower, warmer, level if there was any danger of the fuel freezing.〔AAIB final report, section 1.1 (page 4) "Due to the predicted low temperatures, (crew ) briefed that they would monitor the fuel temperature en route."〕 This did not prove necessary, as the fuel temperature never dropped below −34 °C, still well above its freezing point. Although the fuel itself did not freeze, small quantities of water in the fuel did. Ice adhered to the inside of the fuel lines, probably where they ran through the struts attaching the engines to the wings.〔AAIB final report, section 2.8.5 (page 155) "Ice accumulation during main tank feed"〕 This accumulation of ice had no effect on the flight until the final stages of the approach into Heathrow, when increased fuel flow and higher temperatures suddenly released it back into the fuel.〔AAIB final report, section 2.8.5 (page 155) "Release of accumulated ice on approach"〕 This formed a slush of soft ice which flowed forward until it reached the Fuel/Oil Heat Exchangers (FOHEs) where it froze once again, causing a restriction in the flow of fuel to the engines.〔AAIB final report, section 2.8.5 (page 155) "The fuel flow restriction"〕〔AAIB final report, section 2.8 (page 149)〕 The first symptoms of the fuel flow restriction were noticed by the flight crew at of height and of distance from touchdown, when the engines repeatedly failed to respond to a demand for increased thrust from the autothrottle. In attempting to maintain the instrument landing system (ILS) glide slope, the autopilot sacrificed speed, which reduced to at .〔 The autopilot disconnected at , as the co-pilot took manual control.〔 Meanwhile, the captain reduced the flap setting from 30 degrees to 25 degrees to decrease the drag on the aircraft and stretch the glide.〔〔 〕 The plane passed above traffic on the A30 and the airport's Southern Perimeter road and landed on the grass approximately short of runway 27L.〔 The captain declared an emergency to the control tower a few seconds before landing.〔 During the impact and short ground roll, the nose gear collapsed, the right main gear separated from the aircraft penetrating the central fuel tank and cabin space, and the left main gear was pushed up through the wing. The aircraft came to rest on the threshold markings at the start of the runway. A significant amount of fuel leaked, but there was no fire.〔 Four crew members and eight passengers received minor injuries, and one passenger received serious injuries (concussion and a broken leg).〔〔〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「British Airways Flight 38」の詳細全文を読む スポンサード リンク
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