With his friends' financial investment Dunne formed the Blair Atholl Aeroplane Syndicate to continue his experiments and took up hangar space on the Aero Club's new flying ground at Eastchurch on the Isle of Sheppey. Short Brothers had a manufacturing facility there and were contracted to build the D.5, a broadly similar biplane in which Dunne installed a more powerful 35 hp Green engine. Following a series of increasingly successful flights, on 20 December 1910 Dunne demonstrated the inherent stability of the D.5 to an amazed audience who included two official observers, Orville Wright and Griffith Brewer.