Complex sentence: On 12 June 1909, the prototype Blériot XII became the first aircraft to fly with three people aboard, and Blériot flew it, bearing competition No.23, at "Le Grande Semaine D'Aviation de la Champagne" at Reims between August 22 and August 29 1909.
Split into simpler sentences: On 12 June 1909, the prototype Blériot XII became the first aircraft to fly with three people aboard. Later that year Blériot flew it, bearing competition No.23, at "Le Grande Semaine D'Aviation de la Champagne" at Reims between August 22 and August 29 1909.