1888 - Birth of Conrad Tolendal Lally, Canadian WWI flying ace
1888 - Birth of George W. Thompson, American self-taught aviator, and one of the 1st Coloradan flyers.
1898 - Birth of Geoffrey William Hemming, British WWI flying ace
http://en.wikipedia.org/wiki/Geoffrey_Hemming - http://www.theaerodrome.com/aces/england/hemming2.php
1899 - Birth of Charles Philip Allen, British WWI flying ace
http://en.wikipedia.org/wiki/Charles_Allen_(aviator) - http://www.theaerodrome.com/aces/england/allen1.php
1899 - Birth of Cyril Hayes Sawyer, British WWI flying ace
1904 - Gabriel Voisin successfully flies a modified Archdeacon glider at Berck sur Mer, Picardie. Voisin added a canard to the design. His longest flight on this day was 25 seconds.
1910 - French Emile Dubonnet set a World record with a distance of 109km in 1h 48min and 54sec flying a Tellier monoplane
http://fr.wikipedia.org/wiki/%C3%89mile_Dubonnet - http://aviation.maisons-champagne.com/dir.php?centre=04-bio-dubonnet&menu=11
1912 - Death of Calbraith Perry Rodgers, pioneer American aviator who made the 1st transcontinental airplane flight across the U.S. , crashing his Wright Model B while making an exhibition flight over Long Beach, California, he flew into a flock of birds, causing the plane to crash into the ocean.
1913 - The 2nd competition for seaplanes begins in Monaco.
1919 - A Farman F.60 Goliath, french early twin engine biplane airliner, initially designed as a bomber, flew 14 passengers at an altitude of 6,200 m (20,341 ft)
1926 - Birth of Virgil Ivan Grissom , better known as Gus Grissom, one of the original NASA Project Mercury astronauts and a United States Air Force pilot. He was the second American to fly in space and the first NASA astronaut to fly in space twice.
1927 - Birth of Richard Stephen "Steve" Heyser, USAF Lockheed U-2 pilot whose photographs revealed Soviet medium-range ballistic missiles in Cuba, precipitating the Cuban missile crisis in 1962.
1928 - 1st flight of The Savoia-Marchetti S.64, Italian monoplane developed specifically to contest the world duration and distance records
1933 - A Westland PV-3 Wapiti and A Westland PV-6 Wallace (two-seat general purpose military single-engined biplanes) , become the 1st airplanes to fly over the top of Mt. Everest, at 29,802 ft. the highest point of land on earth, and to photograph the summit from above.
1936 - Amy Johnson, on her way to Cape Town for a new distance record from England, crashed her Percival Vega Gull at Colomb Bechar , Algeria.
1937 - 1st Flight of The Carden-Baynes Bee, novel twin pusher configuration two-seat aircraft built in the UK , with engines buried in the wings. The wings rotated for storage. Financial problems limited the Bee to a single flight
1939 - 1st flight of The Gloster F.9/37 (or Gloster G.39) , British twin-engined design from the Gloster Aircraft Company for a cannon-armed fighter.
1940 - A Short Sunderland, British flying boat patrol bomber, operating off Norway was attacked by 6 German Junkers Ju 88 medium bombers. It shot one down, damaged another enough to send it off to a forced landing and drove off the rest. The Germans are reported to have nicknamed the Sunderland the Fliegendes Stachelschwein ("Flying Porcupine") due to its defensive firepower
1941 - Operation Winch: 12 Hawker Hurricanes are flown off the deck of the aircraft carrier HMS Ark Royal and all arrive safely on Malta.
1944 - German battleship Tirpitz is severely damaged in her mooring in Kaa fjord (Norway) by attacks from the Fleet Air Arm and RAF during operation Tungsten.
1944 - Death of Evelyn Genevieve "Sharpie" Sharp, American aviator, one of the 1st female airmail pilot and one of the original Women's Auxiliary Ferrying Squadron (WAFS) pilot, killed the crash of the P-38 Lightning she was ferrying in Cumberland County, Pennsylvania,
1949 - 1st flight of the Boisavia B-60 'Mercurey', French four-seat high-wing braced monoplane with fixed tailwheel undercarriage light aircraft issued from the B-50.
1951 - Death of Trevor Sidney Wade (known as Wimpy Wade), an English fighter ace of the WWII Battle of Britain, later a test pilot. He was killed test flying the Hawker P.1081 (also known as "Australian Fighter") prototype fighter.
1954 - Death of Constantin 'Kostia' Wladimir Rozanoff, French test pilot, Colonel of the French Air Force, and one of the pioneers of jet aviation, chief-pilot at Dassault Aviation, Killed in the crash of a Mystère IV B during a public low-level flight over Melun Villaroche Aerodrome.
1956 - Death of Jack Armand Cunningham, British WWI flying ace
http://en.wikipedia.org/wiki/Jack_Armand_Cunningham - http://theaerodrome.com/aces/england/cunningham.php
1961 - A LAN Douglas C-47A crashed into a hillside due to inclement weather. On board were many members of the Chilean association football club C.D. Green Cross. 4 crewmembers and 20 passengers died in the crash
1965 - 1st jet-to-jet combat of the Vietnam War occurs: US Air Force mounts the 1st and largest US air strike against the Thanh Hoa Railroad and Highway Bridge in North Vietnam as part of Operation Steel Tiger, which the bridge survives. Despite 873 sorties against it over the next seven years, the bridge will not be destroyed until 1972. The North Vietnamese Air Force claims to have shot down a U. S. Navy F-8 Crusader fighter and in future years celebrates April 3 as "North Vietnamese Air Force Day. "
1965 - Launch of SNAP-10A, 1st and so far only known launch of a U.S. nuclear reactor into space
1966 - Luna 10 (lunik 10) , 1st artificial satellite of the Moon , played back to Earth The Internationale during the 23rd Congress of the Communist Party of the Soviet Union.
1967 - 1st flight of the Mikoyan/Gurevich MiG-23PD, Soviet variable-geometry fighter aircraft, tailed delta similar to the MiG-21 but with two lift jets in the fuselage
1968 - The RCAF's P2V Neptune flew its last operational mission. A few would later be activated when the Argus was grounded after cracks were discovered in some.
1969 - 1st flight of the Robin HR-100, french low wing cantilever monoplane 4 seat tourer, prototype DR253 Regent rebuilt with metal wings.
1969 - Alvin Marks takes off with his Cessna 210 Centurion 'Semper Fl II' for a round the world from Sacramento, California and back.
1973 - Launch of Salyut 2, Soviet space station, 1st Almaz military space station to fly. 2 Weeks later, it lost attitude control and depressurised, leaving it unusable without any crews having visited it.
1975 - Death of Lloyd Carlton Stearman, American aviator and aircraft designer.
1976 - 1st flight of The Harbin SH-5, Chinese maritime patrol amphibian intended for a wide range of duties, including aerial firefighting, anti-submarine warfare (ASW) and air-sea rescue (SAR)
1979 - Death of Maximilien "Max" Conrad, known as the "Flying Grandfather",record-setting aviator.
1980 - The Bombardier Challenger 600 prototype crashed in the Mojave Desert, due to the failure of the release mechanism to detach the recovery chute after a deep stall, killing one of the test pilots (the other test pilot and the flight test engineer parachuted to safety)
1981 - Death of Juan Terry Trippe, American airline entrepreneur and pioneer, and the founder of Pan American World Airways.
1982 - 1st Flight of the Airbus A310-200, medium- to long-range twin-engine widebody jet airliner.
1984 – Squadron Leader Rakesh Sharma is launched aboard Soyuz T-11, and becomes the 1st Indian in space.
1985 - 1st Kamov V-80-01, Soviet design study designation for an attack helicopter, prototype of the Kamov Ka-50 Hokum, '010', crashes, killing the pilot.
1995 - 1st flight of The Comp Air 4 (also known as the Comp Monster), American 4 seat light civil utility aircraft manufactured in kit
1996 - A United States Air Force CT-43A crashed in Croatia while on an official trade mission. The aircraft, a Boeing 737-253 built as a T-43 navigation trainer, was carrying United States Secretary of Commerce Ron Brown and 34 other people. While attempting an instrument approach to Dubrovnik Airport, the airplane crashed into a mountainside.
1997 - Death of Gino P. Santi, American Air Force engineer who developed the modern pilot ejection system.
http://global.britannica.com/EBchecked/topic/523218/Gino-P-Santi - http://www.nytimes.com/1997/04/09/us/gino-p-santi-81-developer-of-pilot-ejection-system-dies.html
2008 - A Blue Wing Airlines Antonov An-28 crashed upon landing at the Lawa Antino Airport of Benzdorp in southeastern Suriname. The plane carried 17 passengers and a crew of two; all perished in the accident.
2008 - ATA Airlines, Inc., formerly known as American Trans Air, American low-cost scheduled service and charter airline based in Indianapolis, Indiana ceased operations.
2008 - ATV-001 'Jules Vernes', unmanned resupply spacecraft developed by the European Space Agency, docks to the ISS.
2009 - Death of Harold Elwood “Bunny” Comstock, USAF WWII fighter ace and vietnam war pilot.
2010 - A Northrop Grumman MQ-8 Fire Scout, American unmanned autonomous helicopter, launched from USS McInerney (FFG-8) detected a "go-fast" open speedboat and a support vessel engaged in smuggling cocaine in the Eastern Pacific, allowing the ship to confiscate 60 kg of cocaine and detain a number of suspects.