In 1907, Alberto Santos Dumont improved the 14 Bis with another biplane, number 15.
Six original period photographs of issue 15.
Authors: Rol & Cia, Branger.
France, 1907.
+/- 12 cm x 17 cm.
Notes in French on the back.
Perfect condition.
Santos Dumont's number 15 was an ambitious biplane prototype developed in 1907, shortly after the success of the 14-Bis. Initially powered by a 50 hp Antoinette engine mounted above the upper wing, the aircraft had wings of great span (11 meters) and extremely narrow, with only 60 cm of chord, totaling an area of 13 m². These wings were divided into three sections by vertical surfaces and presented a pronounced dihedral, like the 14-Bis, in addition to ailerons positioned in front of the wings for lateral control. The covering was made of Okoumé plywood only 3 mm thick, which demonstrates the search for lightness and efficiency. The landing gear consisted of a single wheel at the front junction of the lower wing, while the tail was supported by two long bamboo booms fixed laterally with steel cables. After being damaged during taxi tests on March 27, 1907, the aircraft was repaired and fitted with a powerful 100 hp Antoinette V-16 engine, but despite the modifications, the aircraft never managed to make a successful flight.
These photographs of Santos Dumont's number 15 are of great historical and technical interest, as they clearly show the construction and testing of one of the Brazilian inventor's most ambitious projects after the success of the 14-bis. It is fascinating to observe the details of the biplane, with its long, narrow wings reinforced by vertical surfaces, the Antoinette engine installed high up, and the bold configuration of the landing gear with a single front wheel. The images show everything from the meticulous assembly to the ground tests, with Santos Dumont and his team next to the plane, revealing both the experimental spirit and the elegant aesthetics of his creations. They are extremely rare records of a little-documented phase of his career, in which he sought new advances after conquering the skies of Paris in 1906.
