An airship, with a propeller similar to the ones used by the Wright brothers in Dec. 1903, appears in three pictures in L'Aerophile from April 1902
Propellers, like the ones utilized by the Wright brothers for their alleged 1903 plane, were already in existence that year as the three pictures from 1902 (see the images with Le Girardot airship) demonstrate.
The two brothers claimed in Sep. 1908 they had built their propellers entirely based on calculations and measurements they had made with the help of their wind tunnel. This claim is not credible as long as propellers with the same shape, form, aspect, identical, already existed in 1903 and the two US inventors have never revealed the exact mathematical method by which they designed the propellers.
Source: Le ballon dirigeable Le Girardot, L'Aerophile, April 1902, pag. 75-76,
L'Aérophile (Paris)
The propellers allegedly used by the Wright brothers on their 1903 Flyer. As can be remarked, they are identical to the ones of Le Girardot airship.
Source:
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1903 Wright Flyer I
- Library of Congress,
[1903 machine, front view]