In the mid-1930s, a French carpenter’s dream put aviation within reach of the ordinary man. Henri Mignet’s Flying Flea — the Pou-du-Ciel, or “Louse of the Sky” — was a tiny wooden aeroplane that anyone could build in a garden shed from a book of plans, with no pilot’s licence and, Mignet cheerfully insisted, barely any flying skill.

Thousands believed him. Across France, Britain and beyond, amateurs hammered together Fleas from spruce and fabric and taught themselves to fly. It was the drone craze of its day — a genuine popular aviation movement.

Then the Fleas began to dive into the ground, and no one aboard could pull them out. What began as a joyful democratisation of flight turned, within a couple of years, into one of aviation’s most infamous cautionary tales.

A Model T for the sky

Henri Mignet was a self-taught French designer who wanted an aircraft simple enough for anyone to build and fly. After years of prototypes, he made the first flight of his HM.14 on 10 September 1933. In 1934 he published Le Sport de l’Air, a book giving complete plans and instructions so readers could construct and fly their own Flea without specialist help. Translated into English in 1935, it prompted hundreds of people around the world to start building.

The Flea was deliberately radical. It was a tandem-wing design with just two flying controls — a stick and a rudder, no ailerons and no rudder pedals. The stick pivoted the front wing to control pitch and worked the large rudder for turns.

The craze

The little aircraft caught the public imagination completely. By 1936 it was estimated that construction cost about £75 and that some five hundred Fleas were under way in Britain alone. Mignet’s original prototype was powered by a modest 17 hp motorcycle engine, spanned about 19.5 ft, and weighed roughly 450 lb gross. It was, by any measure, a genuine people’s aeroplane.

The appeal was freedom: build it yourself, in your own time, and go flying. For a brief moment the Flea looked like the future of grassroots aviation.

The dive with no recovery

Then came the crashes. Under certain conditions the Flea could enter a shallow dive from which no amount of stick could recover it. The cause was a deadly interaction between the two closely spaced wings: when the front wing reached a high angle, airflow deflected off it accelerated over the rear wing, sharply increasing its lift and pushing the nose down. The pilot’s instinct, to pull back, only made things worse.

Because Mignet had tested his prototype with a low-powered engine, he never met the problem; it emerged only when builders fitted bigger engines. In Britain, restrictions followed a fatal crash at Penshurst airfield, Kent, on 4 May 1936. Wind-tunnel tests at the Royal Aircraft Establishment and in France then pinned down the flaw.

Redeemed, too late

Changes to the airfoil and wing spacing cured it, and later Mignet designs flew perfectly safely — the basic layout has since proved sound in hundreds of homebuilts and microlights. But the wave of bad publicity had done its damage.

The Flea never fully shook its dangerous reputation, and the craze burst as quickly as it had bloomed. Yet Mignet’s real legacy survived: the idea that flight need not be the preserve of the rich or the professional — that an ordinary person, with plans and patience, could build wings in a shed and fly.

Sources: Wikipedia; Smithsonian National Air and Space Museum; Newark Air Museum; RAF Museum; EAA; “Flight” magazine archive (1936).