One of the most glaring inconsistencies with the Gustave Whitehead claim, is what happened after his supposed August,1901 flight ..... nothing.
If Whitehead flew in August of 1901, he had over a 2 year head start on the Wright Brothers. Set aside the claims and counter claims over supposed witnesses and misidentified photos, etc of his first flight, if Gustave Whitehead had flown in 1901, why didn't he fly again, and if he did why wasn't there proof of those flights? One would think, after a first successful flight he would set about perfecting his invention, yet nothing.
Now compare that with the Wright Brothers. In the two years following the initial flight in December 1903, the Wright Brothers perfected their design of the Wright Flyer through subsequent aircraft, and made hundreds of flights. All thoroughly documented.