1907 – Horatio Phillips achieves the first, limited, powered heavier-than-air flight in the United Kingdom when his multiplane makes a 500 ft (150 m) hop.

1909 – A crowd at the Centocelle Field, Rome, Italy, sees Wilbur Wright make a 10-minute flight in which he reaches an altitude of 98 feet.

1909 – Wilbur Wright makes five flights in Centocelle, Italy with King Victor Emmanuel III of Italy present. During one flight, a Universal News Agency cameraman accompanies him and takes the first motion pictures from an airplane in flight.

1912 – Harriet Quimby becomes the first woman to fly the English Channel.

1918 – The Royal Flying Corps and Royal Naval Air Service combine to form the Royal Air Force. The Women’s Royal Air Force is formed at the same time.

1918 – Manfred von Richthofen, aka The Red Baron, shoots down his 79th and 80th victims marking his final victories before his death the following day.  The “Red Baron” and “ace of aces” is shot down and killed. By the time of his death, he had claimed 80 victories. Credit for his kill is given to Canadian Cpt Roy Brown, but this is disputed by others who claim that he was killed by ground fire from Australian troops.

1933 – United States Navy airship USS Akron, encounters severe weather and crashes into the Atlantic off the coast of New Jersey. 73 passengers and crew, including Rear Admiral William A. Moffett, were killed. It did not have the Curtiss F9C Sparrowhawks deployed aboard when it was lost. The new Naval Airship Station at Sunnyvale, California is named Moffett Field in honour of the lost admiral.

1933 – Two British aircraft, the Westland PV-3 and Westland PV-6 make the first flight over Mount Everest

1937 – The first commercial flight across the Pacific is made as a Pan-American Boeing 314 Clipper seaplane arrives in Hong Kong.

1943 – The first production model Boeing B-29 rolls out of the Wichita, Kan., plant

1943 – P-38 Lightnings intercepted Japanese aircraft and take down two Mitsubishi bombers over Bougainville, killing Admiral Yamamoto, Japan’s leading military strategist.

1947 – The International Civil Aviation Organization (ICAO) is officially founded in Montreal, Canada. It is an intergovernmental organization, established to regulate air transportation on a worldwide basis, its authority restricted only by the number of signatory nations.

1948 – A North American YP-86 becomes the first jet-powered aircraft to exceed Mach 1.  (The Bell X-1 was rocket powered)

1952 – First flight of the Boeing B-52 Stratofortress.

1955 – Trans-Canada Airlines introduced the Vickers Viscount airliner into regular service, making it the first North American airline to use turbine power aircraft.  You can sit in the cockpit of a Vickers Viscount at Wings of History.

1959 – Mercury program – NASA announces the selection of the United States’ first seven astronauts, which the news media quickly dub the “Mercury Seven”.

1963 – Joseph A. Walker flies the North American X15 A to a height of 82,600 m (271,000 feet) and, having flown higher than 50 miles, he qualifies for astronaut wings.

1967 – First flight of the Boeing 737

1970 – An oxygen tank aboard Apollo 13 explodes, putting the crew in great danger.  The crippled Apollo 13 spacecraft and its three astronauts returns to earth safely.

1981 – Launch: Space shuttle Columbia STS-1 at 12:00:03 UTC. It is the first reusable orbital spacecraft flight and the first flight of Columbia.

1990 – Launch: Space Shuttle Discovery STS-31 at 12:33:51 UTC. Mission highlights: Hubble Space Telescope deployment.

1994 – The Boeing 777 twinjet, the newest member of the Boeing jet family, rolls out.

2005 – First flight of the Airbus A380 from Toulouse, France.

2013 – Virgin Galactic‘s commercial spacecraft SpaceShipTwo makes its first powered flight. Released by its jet-powered mothership White Knight Two after a 45-minute climb at an altitude of 48,000 feet (14,631 meters) over the Mojave Desert, SpaceShipTwo burns its engine for 16 seconds, climbing to 55,000 feet (16,764 meters) and reaching a speed of Mach 1.2 before gliding to a landing at Mojave Air and Space Port in Mojave, California, after 10 minutes of independent flight. Mark Stuckey is the pilot and Mike Alsbury the co-pilot for the flight.^[1]

The above is a partial list of aviation events that took place in the month of April.  A more complete listing can be found here.