The principle of this was not new, having been demonstrated to the French Academy of Sciences in 1784 by M. Launoy, a naturalist, and M. Bienvenu,[1] and was known by Sir George Cayley, but it was the first use of twisted rubber to power a flying model.

The Planophore was successfully flown at the Tuileries Gardens in Paris in front of members of the Société Aéronautique on 18 August 1871, flying a distance of 131 feet (40 m) and staying in the air for 11 seconds.

The 1876 aircraft was drawn in detail for the purpose of patenting the ideas it incorporated, and had many remarkably advanced features, including electrically operated elevators, a fully enclosed cabin for the pilot, a retractable undercarriage, and the use of a pair of propellers rotating in opposite directions to eliminate the torque reaction caused by a single propeller.

He also participated in lighter than air experimentation, and produced a number of ingenious devices, including a differential barometer to show the rate of ascent or descent.

Alphonse Pénaud was unable to obtain any financial backing for his ambitious design and committed suicide on 22 October 1880, aged 30.