New Delhi: Was the first manned flight in 1891 or in 1903? The question will be rekindled at next month's Berlin Air Show. Conventional wisdom has it that the first powered manned flight was by the Wright brothers at Kitty Hawk in December 1903. The organisers of the ILA Berlin Air Show that will run from June 1 to 4 beg to disagree. They say they will be "marking a special anniversary in the history of aviation" when, 125 years ago in 1891, "Otto Lilienthal became the first man to fly an aircraft". For good measure, the German Aerospace Centre (DLR) "will be displaying an exact replica of Lilienthal's glider to the public at the central ILA Plaza. In the restaurant area in Hall 4 the Society for the Preservation of Historic Sites of German Aviation History (GBSL) will be hosting an exhibition of the aviation pioneer's achievements", the organisers say. The catch here is the word "glider". It's an aircraft, no doubt, but it can't take off on its own, unlike the Wright flyer that the brothers christened their machine. But then, the respected Jane's All the World's Aircraft stirred the pot some years ago by claiming that the first manned flight was in August 1901 by Gustave Whitehead, an aviation pioneer from Connecticut. Still, let's recognise Lilienthal's achievements -- never mind the "powered" or "unpowered" bit. "Lilienthal is recognised as the first person to have undertaken manned flight. In 1891 he made several successful flights with a glider that he himself had built. Balloons with which flights had already been made are not classified as aircraft as they are lighter than air. "Lilienthal's experiments paved the way for the Wright brothers' first powered flight in the USA and for the later achievements of aviation pioneers such as Hugo Junkers. This was made possible by Lilienthal's scientific publications and some spectacular photos which caused a sensation both at home and abroad," the Berlin Air Show organisers say. To ths end, the DLR has built "an exact replica of the world's first production aircraft and scientifically examined it in a wind tunnel", the organises say, adding: "The scientific evaluation was undertaken by the Göttingen-based DLR Institute for Aerodynamics and Flow Technology." From Lilienthal's many designs, the one that was reproduced was that of his "standard gliding apparatus" as "this was the world's first production aircraft. Scientists also hope to find out more about the reasons for his fatal accident". That happened on August 9, 1896, when his glider pitched forward and headed down quickly and he fell from a height of about 15 metres while still in the glider, dying 36 hours later, according to the proceeds of the inquiry into the mishap. The replica was assembled by the Otto Lilienthal Museum in Anklam according to Lilienthal's original drawings. "His gliders have been reproduced quite often, but this is the first time a historically correct replica has been made. In order to achieve this, a certain amount of research was required. Thus, a thorough examination was made of fabric samples from Lilienthal's remaining gliders in order to determine their quality," the organisers say.