Henri Mignet dreamed of creating a Model T of the air, an airplane for the common man, hence the term Pou du Ciel.

In 1935, it was translated into English in Britain and serialised in Practical Mechanics in the USA, prompting hundreds of people around the world to build their own Flying Fleas.

[3] Mignet's original HM.14 prototype aircraft was powered by a 17 hp (13 kW) Aubier-Dunne 500 cc two stroke motorcycle engine.

Also some homebuilders attempted to simplify construction by modifying components such as the wings tips curving up, resulting in extremely dangerous airplanes and deadly accidents that forced the air authorities to ban building more of them.

[5] Studies in the UK and France revealed the problem (the HM.14 was small enough to fit in wind tunnels in both countries usually used for scale models of larger aircraft) and corrections were made to the design.

[4] In the United Kingdom, restrictions were placed on Flying Fleas, following a fatal crash on 4 May 1936 at an air display at Penshurst Airfield, Kent.

As speed built up, the rear wing, operating at a greater angle of attack would gain lift and pitch the aircraft's nose further downward.

When builders started putting larger engines on them and expanding the flight envelope, the wing interference problem surfaced.

These tests, together with those conducted by the French Air Ministry, discovered if the angle of attack of the front wing fell below −15° insufficient pitching moment was generated to raise the nose.

[15] Changes to the airfoil section and wing spacing prevented aerodynamic interference and later Mignet Flea designs incorporated these changes.

[citation needed] By 1939, there were many improved Flying Fleas in the air, but the aircraft never completely overcame its dangerous reputation.

Modern HM.14 builders generally adapt the airfoil and rigging or even the entire wings from later Mignet models, such as the HM.360, to the fuselage of the HM.14 to create a safe and reliable aircraft with the retro look of the original.