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Accident to USAF B52D

On 11 February 1958 a Boeing B52D crashed in South Dakota, USA. During a go-around engines 1, 2 and 5 had an uncommanded reduction in engine power. During the subsequent approach, power was gradually lost from all the engines, despite the selection of full thrust. The aircraft struck the ground some 3,500 ft short of the runway threshold fatally injuring three of the crew. Despite a significant post-crash fire, ice was discovered within the aircraft fuel system.A subsequent inquiry attributed the engine power loss to icing of the engine fuel pump screens, causing a restricted fuel flow to the engines. Contributory factors were excess water/ice in the fuel tanks and no bypass on the fuel pump screen.

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Corrosive brown fungal growth on the internal surfaces of an aircraft fuel tank

Blocked filters are usually the first sign of microbial contamination

Contaminated FuelThe Dominican de Aviación Santo Domingo DC-9 air disaster occurred on February 15, 1970.All 97 passengers and five crew members died in the air crash into the Caribbean Sea.

Two minutes after take-off, it lost power on the right engine. The pilots tried to turn around, asking the Las Americas Airport control tower for clearance for an emergency landing, but, during the turn, the left engine also lost power, and,because the aircraft was in a turn around motion when the left engine failed, the jet plunged into the sea, in what has been the only jet airliner tragedy to date for either Las Americas or Luis Muñoz Marín International Airports.To the FAA and Dominican aviation authorities, it seemed rather strange that dual engine failures would occur on such new aircraft, and the subsequent investigation showed that the airliner had been filled with contaminated fuel which caused both engines' failures.

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Corrosivity

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Corrosivity

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Corrosivity

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תיאור סכמאטי מופשט של תהליך קורוזיה הנובע מפעילות מיקרואורגניזמים

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Icing

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Icing

UAL Corp.'s United Airlines, and AMR Corp.'s American Airlines are taking precautionary steps to ensure fuel quality and re-evaluate fuel characteristics before investigators release preliminary findings. While it is common for airlines to ramp up safety efforts in the wake of a high-profile crash, they typically wait until the release of such findings or early safety recommendations by regulators or manufacturers.

according to these people, and is reviewing , testing fuel at airportsit uses for accepting and control systems -qualityUnited is reassessing certain American has launched an effort to determine if a different type of jet fuel procedures its mechanics use to drain water from jetliner fuel tanks.

.could better withstand temperature extremes on the longest and coldest polar routes, other officials said, cooler systems-whether ice crystals may have clogged the plane's dual oilThe moves come as U.S. and British investigators are focusing on

according to people familiar with the details. The radiator-like devices use fuel flow from each of the wing tanks to cool engine oil, and fuel then flows from there to the nearby engine during flight.

to warnings of ed Investigators also want to determine how mechanics who worked on the aircraft before a pair of earlier flights may have reactAn internal Federal Aviation Administration memo last month said "a maintenance message indicating excessive . potential ice buildup in the fuel

water in the center tank was set during taxi on the two previous flight legs, although it cleared itself both times."fuel system wasn't fuel tanks only on the ground, so part of the puzzle is what mechanics did to ensure the 777 Water can be drained from Boeing

United's routine procedures call for removing excess water after every several hundred flight hours.. contaminatedUnited, American and Rolls-Royce Group PLC, which made the engines on the plane that crashed, have declined to comment on the investigation. Boeing Co., which said its 777 aircraft flew for 12 years and about 3.6 million hours world-wide without a major accident, said "it would be inappropriate to comment at this stage." The crash didn't result in fatalities.The analysis and safety-oversight efforts by the airlines haven't uncovered any significant new icing-related hazards or resulted in operational

new safety lease rechanges. British regulators are expected to issue an update on the probe within a few days, though they don't appear ready toglobal aviation industry are following the The latest moves highlight how closely large segments of the . mandates or recommendations

cal or art jetliner with no apparent mechani-the-of-believed to be the first time ice contamination in fuel brought down a large, state, investigationcomputer malfunctions.

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A very short introduction to turbulence

Kelvin-Helmoltz instability.

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The first graphic is a picture of billow clouds (the fancier name is altostratus undulatus clouds)

The picture is taken from:: C.Donald Ahrens: Meteorology Today, 9th edition, Books/Cole 2009.

: A lab experiment and is taken from: G.L. Brown and A. Roshko, online available Density effects and large structure in turbulent mixing layers, Journal of Fluid Mechanics 64 (4), pp. 775-816 (1974), ISSN 0022-1120.

Isn’t it strange that clouds in the sky would show the same pattern as some gases in a small laboratory experiment? The reason for this is not quite understood today .

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ערכי Re בספיקות 100-400 מק" ש בצנרת בטווח קטרים " 10 - " 4

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כיער

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JIG – PublicationsThe Joint GuidelinesThe Joint Guidelines for Aviation Fuel Quality Control and Operating Procedures consist of internationally agreed procedures forhandling aviation fuel at airports and upstream aviation fuel facilities. The Joint Guidelines include recommended practice for fuel sampling and testing, depot and fuelling vehicle design features, and procedures for storage and delivery of aviation fuel to aircraft.

The Joint Guidelines, Issue 10 (July 2008) is published as three separate documents:

JIG 1Guidelines for Aviation Fuel Quality Controland Operating Procedures for Joint Into-plane Fuelling Services

JIG 2Guidelines for Aviation Fuel Quality Control and Operating Procedures for Depots

JIG 3Guidelines for Aviation Fuel Quality Controland Operating Procedures for Jointly Operated Supply and Distribution Facilities

JIG 1 and JIG 2 are endorsed by IATA.JIG 4The Guidelines for Aviation Fuel Quality Control and Operating Procedures for Smaller Airports, first issue (May 2007) is applicable to road/rail supplied smaller airport locations and is also endorsed by IATA.

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Web Sources

•• VelconVelcon Filters, LLC ( Ben TaylorPresenting)•http://npma-fuelnet.org/certification/Track101/4-Taylor-OperatingMonitoringandChangingFilterCartridges-TheRightWayEvenWhenSwithingFuels-Velcon.pdf

•CHEVRON - Aviation Fuels Technical Review•http://www.cgabusinessdesk.com/document/aviation_tech_review.pdf

•Army Aviation Accident Prevention Program•http://ebookbrowse.com/gdoc.php?id=229624709&url=47f561125534a6553923a09ac82b24dc

•Gamon - GamGrams הורדה חופשית) – (דפי מידה קצרים הסוקרים בעיות נפוצות באחזקת מערכות דלק תעופתח•http://www.gammontech.com/mainframe/Pgamgrams.htm

•Aviation Fuel Properties HandBook•http://www.dtic.mil/dtic/tr/fulltext/u2/a132106.pdf

•EXXON MOBIL - World Jet Fuel Specifications with Avgas Supplement, by Kenneth A. Warren•http://www.exxonmobilaviation.com/AviationGlobal/Files/WorldJetFuelSpec2008_1.pdf

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