Selected article

Microburst schematic from NASA. Note the downward motion of the air until it hits ground level, then spreads outward in all directions. The wind regime in a microburst is completely opposite to a tornado.

Wind shear itself is amicroscale meteorological phenomenon occurring over a very small distance, but it can be associated withmesoscale orsynoptic scale weather features such as squall lines and cold fronts. It is commonly observed nearmicrobursts anddownbursts caused bythunderstorms, weather fronts, areas of locally higher low level winds referred to as low level jets, nearmountains, radiation inversions that occur due to clear skies and calm winds, buildings, wind turbines, and sailboats. Wind shear has a significant effect during take-off and landing of aircraft due to their effects on steering of the aircraft, and was a significant cause of aircraft accidents involving large loss of life within theUnited States.

Sound movement through the atmosphere is affected by wind shear, which can bend the wave front, causing sounds to be heard where they normally would not, or vice versa. Strong vertical wind shear within the troposphere also inhibitstropical cyclone development, but helps to organize individual thunderstorms into living longer life cycles which can then producesevere weather. Thethermal wind concept explains with how differences in wind speed with height are dependent on horizontal temperature differences, and explains the existence of thejet stream. (Full article...)

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Did you know

..that an aircraft'spitot-static system allows a pilot to monitorairspeed,Mach number, altitude, and altitude trend?...thatWing CommanderStanley Goble andFlying Officer Ivor McIntyre, piloting a single-enginedseaplane(pictured), became the first men tocircumnavigateAustralia by air in 1924?...thatYekaterina Zelenko was the only woman to perform anaerial ramming and the only female pilot in theWinter War?

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• May 29:Austrian Airlines cancels Moscow-bound flight after Russia refuses a reroute outside Belarusian airspace
• August 8:Passenger flight crashes upon landing at Calicut airport in India
• June 4:Power firm helicopter strikes cables, crashes near Fairfield, California
• January 29:Former basketball player Kobe Bryant dies in helicopter crash, aged 41
• January 13:Iran admits downing Ukrainian jet, cites 'human error'
• January 10:Fire erupts in parking structure at Sola Airport, Norway
• October 27:US announces restrictions on flying to Cuba
• October 3:World War II era plane crashes in Connecticut, US, killing at least seven
• September 10:Nevada prop plane crash near Las Vegas leaves two dead, three injured
• August 6:French inventor Franky Zapata successfully crosses English Channel on jet-powered hoverboard

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Selected biography

Selected Aircraft

TheAvro Lancaster was aBritish four-engineSecond World Warbomber aircraft made initially byAvro for the BritishRoyal Air Force (RAF). It first saw active service in 1942, and together with theHandley-Page Halifax it was one of the main heavy bombers of the RAF, theRCAF and squadrons from otherCommonwealth andEuropean countries serving withinRAF Bomber Command. The "Lanc" or "Lankie," as it became affectionately known, became the most famous and most successful of the Second World War night bombers, "delivering 608,612 tons of bombs in 156,000 sorties." Although the Lancaster was primarily a night bomber, it excelled in many other roles including daylight precision bombing, and gained worldwide renown as the "Dam Buster" used in the 1943Operation Chastise raids on Germany'sRuhr Valley dams.

• Span: 102 ft (31.09 m)
• Length: 69 ft 5 in (21.18 m)
• Height: 19 ft 7 in (5.97 m)
• Engines: 4× Rolls-Royce Merlin XX V12 engines, 1,280 hp (954 kW) each
• Maximum Speed: 240 knots (280 mph, 450 km/h) at 15,000 ft (5,600 m)
• First Flight: 8 January 1941
• Number built:7,377

Today in Aviation

April 2

• 2012 –UTair Flight 120, a twin-engineUTair AviationATR-72-201, crashes in westernSiberia near the city ofTyumen shortly after takeoff fromRoschino International Airport, killing 31 of the 43 people on board and critically injuring all 12 survivors.^[1][2][3]

• 2010 – An Embraer EMB 312 Tucano of the Brazilian Air Force "Smoke Squadron" crashed during an airshow at the Aeroporto Federal de Lages. The pilot, aged 33, died in the crash.

• 2009 – Chemtrad Aviation Britten-Norman Islander RP-C764 crashes at Baggao, Philippines, killing all thirteen people on board. The aircraft was destroyed.

• 2009 – A Spanish Air Force F/A-18 Hornet crashes in northern Spain. Pilot ejects safely.

• 2005 – Royal Australian Navy Westland Sea King Mk50a, N16-100, '(9)02', helicopter Shark 02 of 817 Squadron RAN crashes on the Indonesian island of Nias while providing humanitarian support following the 2005 Sumatra earthquake, killing 9 Australian Defence Force personnel on board.

• 2003 – A UH-60A Black Hawk (94-26557) of B Company, 2–3rd Aviation Regiment is shot down nearKarbala, killing 7 soldiers and injuring 4 more.^[4]

• 2003 – F/A-18C Block 46 Hornet 164974 ofVFA-195 is shot down by a US Patriot missile, killing the pilot.^[5][6]

• 2002 – A United States Navy Sikorsky MH-53E Sea Dragon of HM-14 BuNo 163051 crashed on the runway at Bahrain International Airport. All 18 men and woman on board survived with only a few cases of minor injuries.

• 1997 – A Boeing 777, powered by twin Rolls-Royce Trent 892 turbofans, returns to Seattle to set a new Eastbound speed around the world record of 553 mph. En route, the twinjet sets a Great Circle distance without landing record of 12,455.34 miles when flying from Seattle to Kuala Lumpur, Malaysia.

• 1997 – Craig D. Button (November 24, 1964—April 2, 1997), a United States Air Force pilot, dies when he mysteriously crashes an Fairchild-Republic A-10 Thunderbolt II aircraft in the Colorado Rockies. Before the incident, Captain Button inexplicably flew hundreds of miles off-course without radio contact, appeared to maneuver purposefully and did not attempt to eject before the crash. His death is regarded as a suicide because no other theory explains the events. His aircraft carried live bombs, which were never recovered. It took three weeks to find the crashsite. During that time, there was widespread public speculation about Captain Button's intentions and whereabouts.

• 1987 – ARoyal Air ForceVickers VC-10 sets a new record time between the UK and Australia, landing inPerth after a flight of 16 hours 1 min.

• 1986 –TWA Flight 840, a Boeing 727, is bombed by Palestinian militants, killing four out of 121 people on board. The plane manages to land safely in Athens.

• 1984 – Squadron Leader Rakesh Sharma is launched aboard Soyuz T-11, and becomes the first Indian in space.

• 1982 – The Falklands War begins as Argentina invades the Falkland Islands and South Georgia Island.

• 1982 – An Armada de la República Argentina (ARA) Westland Lynx HAS.2 from the 1ra Escuadrilla Aeronaval de Helicópteros supporting the Argentinian invasion of the Falklands crashes into the sea near the ARA Santísima Trinidad.

• 1971 – Last internal Yukon flight from Victoria to Trenton.

• 1969 –LOT Polish Airlines Flight 165, an Antonov An-24, crashes in southern Poland, killing all 53 people on board.

• 1965 – First flight of thePartenavia Oscar

• 1957 – First flight of theShort SC.1 (CTOL)

• 1956 –Northwest Orient Airlines Flight 2, a Boeing 377 Stratocruiser, ditches into Puget Sound after takeoff from Seattle-Tacoma International Airport after the cowl flaps are incorrectly set for takeoff; four passengers and a flight attendant die, probably of hypothermia, while waiting for rescue; 33 survive.

• 1955 – Trans-Canada Airlines introduced the Vickers Viscount airliner into regular service, making it the first North American airline to use turbine power aircraft.

• 1949 – First flight of theSNCASE Armagnac

• 1944 – The first United States Army Air Forces B-29 Superfortress arrives at Calcutta, India, after an 11,530-mile (18,567-km) trip from Kansas, which includes stops at Presque Isle, Maine; Gander, Newfoundland; Marrakech, Morocco; Cairo, Egypt; and Karachi, and a 2,700-mile (4,348-km) non-stop transatlantic flight between Gander and Marrakech.

• 1937 – Swedish airplane manufacturer Svenska Aeroplan Aktiebolaget (SAA is established in Trollhättan, Sweden.

• 1917 – The prelude to the battle of Vimy Ridge began as the Canadian gunners started pounding the German defences, from small howitzers to huge naval guns, using a nearly limitless supply of ammunition. It was the largest artillery poundings in history up to that point, using over one million shells. The attack lasted for seven days, and was loud enough to be heard in London. Germans in the front line trenches later called it “the week of suffering. ”

• 1794 – Establishment of the first airship company in theFrench Army who use a balloon namedEntreprenant forreconnaissance of theAustrian forces at theBattle of Fleurus. Two companies of balloon observers are formed, but disband the following year.

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