In a letter written on Nov. 9, 1905, Octave Chanute claimed he had seen a 500 m flight performed by the Wright Brothers.
However, from the content of the letter and its general tone, Chanute appears to act as the lawyer of the two brothers, trying to convince Captain Ferber (see:
http://en.wikipedia.org/wiki/Ferdinand_Ferber) about things he had not seen.
In December 1905, L'Aérophile dedicated a long text to the Wright brothers and their claimed spectacular flights of Sep-Oct 1905. The most interesting thing in the article is a letter written by Octave Chanute, on Nov. 9, 1905 and addressed to Ferber, in which Chanute advised this french captain to trust the Wright brothers regarding their claims about the long runs in the air that had taken place in 1905. Chanute even mentioned he had witnessed a 500 meters flight at an unspecified date, definitely not in Sep-Oct 1905 or after (this information results from the letter). The only evidence, about the claimed long flights in the beginning of Oct. 1905, was personally obtained by Chanute directly from some eye witnesses, who were close friends of the Wright brothers. They assured him one week before Nov. 9, 1905 (so definitely after the Wrights' last flight on Oct. 5, 1905) that the long runs in the air had taken place, indeed.
The letter written in French by Chanute, as it was published by L'Aérophile:
"
D'autre part, le capitaine Ferber avait reçu de M. Chanute la lettre suivante, écrite en français, qu'il avait provoquée pour arriver à un premier contrôle des assertions Wright :
Chicago, III., 9 novembre 1905
Cher capitaine Ferber,
Je viens de recevoir votre lettre du 26 octobre. Je crois que vous pouvez octroyer toute confiance à ce que les Wright vous ont écrit de leurs accomplissements (sic). Je n'ai vu, de mes yeux, qu'une petite envolée d'un demi-kilomètre, mais ils m'ont mandé leurs progrès de semaine en semaine et leurs amis intimes qui ont vu les longs parcours du commencement d'octobre, m'ont confirmé verbalement la semaine dernière, quand j'étais à Dayton, pour voir une envolée projetée de 60 kil. en une heure, qui n'a pu avoir lieu par raison d'un grand orage.
Les Wright se sont inspirés de l'exemple de la France qui a tenu secrets ses progrès de ballons dirigeables depuis 1885. Ils se sont arrangés avec leurs journaux à Dayton. Il y a bien eu une indiscrétion et un article publié, mais sa circulation a été supprimée.
Les Wright devaient vous écrire vers le 4 novembre.
Agréez, cher monsieur, l'expression de mes sentiments les meilleurs.
(Signé) : O. CHANUTE."
English Translation:
"On the other hand, Captain Ferber had received the following letter, written in French, from Mr. Chanute who had been provoked by him (by Ferber) to verify somehow the assertions of the Wrights:
Chicago, Ill., November 9, 1905
Dear Captain Ferber,
I have just received your letter of October 26. I think you can trust what the Wrights wrote to you regarding their achievements (sic). I have not seen with my own eyes anything excepting a short flight of half a kilometer but they informed me weekly about their progress and their close friends, who saw the long runs from the beginning of October, verbally confirmed to me, last week when I was in Dayton to see a projected 60 km flight in an hour, which did not take place because of a great storm.
The Wrights are inspired by the example of France which has kept the progress of its airships secret since 1885.
They arranged with their newspapers in Dayton. There was an indiscretion and an article got published, but its circulation was suppressed.
The Wrights have to write to you around November 4.
Accept, sir, my best wishes.
(Signed): O. CHANUTE."
Source: "Letter sent by Octave Chanute to captain Ferber and published by L'Aérophile on December 1905 at pag. 268 (middle of the page)", see:
L'Aérophile (Paris)
The entire article: "Les Frères Wright et leur Aéroplane à moteur L'origine et les pièces du débat. — Exposé des faits avancés par les Wright. — Objections et possibilités. — Premiers résultats de l'enquête. ", L'AÉROPHILE, Directeur-Fondateur : GEORGES BESANÇON, 13e Annee — N°, 12 Décembre 1905 pag. 165-272,
L'Aérophile (Paris)
This letter is quite suspicious. Chanute had seen, without any doubt, some unpowered flights performed by the Wright brothers. From the text in the letter it appears the 500 meters flight witnessed by Chanute was powered and self sustained but it is not clear 100%. It appears Chanute teamed up with the two brothers and he tried to give a plus of credibility to the lies perpetrated by the Wrights.