01/31/2009. Remarks by Kees Kort: "The French Ateliers d'Aviation Lioré et Olivier was formed in March 1912 and the first produced aircraft, the LeO 4, designed by the company engineer Leflot, was not taken into series production.

Shown in its original configuration, the LeO 4 featured the distinctive umbrella-shaped upper wing with curved and wavy trailing edges. This construction was in the end not successful and the machine was converted with a conventional straight wing, the modified version got the designation LeO 4/1. In 1916-1917 Lioré et Olivier built great numbers of Sopwith 1˝ Strutter biplanes, the LeO 4/1 was developed as a replacement for the Sopwith.

This picture is the only known one of the original LeO 4 as far as I know."