20 April 1861 (USA): Thaddeus S.C. Lowe, American inventor and balloonist, makes a balloon trip from Cincinnati, Ohio to the South Carolina coast in 9 hours.

20 April 1935 (Australia): The first passengers leave for Australia on a new Imperial Airways/QANTAS service; the first Australian departures were made from Brisbane on April 17.

20 April 1943 (South Pacific): USAAF 7th AF Consolidated B-24 “Liberators” made the first attack on Tarawa.

20 April 1959 (USSR): Aeroflot puts the 84 to 110-seater Ilyushin IL-18, its first turboprop, into service from Moscow to Alma Ata, Kazakhstan, and Adler, now Sochi, on the Black Sea.