Flying Flea

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It was with his friend Pierre Colin, an instructor during the First World War, that Mignet tried to learn to fly a conventional aeroplane, the Potez 43.0 F-AMJS. In the summer of 1932, Mignet accumulated about thirty hours in the Potez, some in the pilot's seat, but many just as observer and navigator on trips around northern France and Belgium. 'A machine quite beyond me,' was Mignet's assessment of the Potez.

No matter what, these flying experiences were to have a major influence on Mignet's philosophy about flying and the mechanics of piloting a flying machine. In his flowery and prophetic style he grouped his experience of both types of aircraft into a comparison: 'Luck has so arranged - oh my guardian angel that I should pilot the Pou du Ciel before taking in hand seriously the control of an aeroplane. My reactions were formed by sane instinct. All the stuff learned in ten consecutive hours of flying an aeroplane vanished in 100 metres of flight on the Flea.'

His denigration of the conventional aeroplane, or perhaps just himself as a pilot of a 'normal' aeroplane, then comes to a monumental conclusion: 'What is it in fact, this leaming to fly? To be precise, it is to learn NOT to fly wrong.'

Did the Flea come into existence because of Mignet's dissatisfaction at his skills in piloting a conventional aeroplane, or was it the Flea and its unconventional design and controls that caused Mignet, its creator, to crusade for it with the tunnel vision of a zealot? A classic chicken and egg argument. Whatever the origins of the venom, Mignet was not just disillusioned with the conventional aeroplane: 'The aeroplane is frightening,' he wrote.

This character assassination of the conventional aircraft was because throughout his design experience so far, Mignet had found the 'normal' aircraft to be wanting as an amateur-built, fun aeroplane. He was looking for a cheap, safe, easy-to-fly, lightweight aeroplane for the man in the street.

Mignet was cuite content to accept the use of conventionally controlled aeroplanes for air transport but another system would be needed for true amateur aviation. The tenets Mignet listed for his concept still hold true today -and work just as well on today's designs.

 

Mignet's criteria were:
Security of construction.
Security by means of a margin of speed.
Security by means of stability of shape.
Security by rational controls for flight.
Economy - of materials, dimensions,
powerplant and running costs.
Lightness of the aircraft; which implies
smallness, small powerplant and cheapness.

Mignet wrote at length about these in the French aviation magazine Les iiles for 28 January 1932 in relation to aeroplanes of less than 220 lb empty weight and concluded that it was possible to make such a craft that was no heavier than the average pilot 176 lb 'To fly very cheaply one must make something very small.'

By combining the idea of a small lightweight aeroplane with Mignet's enthusiasm for the simplicity of piloting an aircraft the stage was set for the Flea to be born. But how did the unique Flea formula come about?

The Flea was the culmination of many years of research, study and experimentation. Even before the Wright brothers had flown in 1903, Mignet had concluded that birds were so free in the air because they could control directly the amount of lift employed at any moment. Model kites and aeroplanes towed behind a bicycle showed him that the kite remained stable, but the aeroplane was unstable, spinning around and around. Mignet concluded, rightly, that an aeroplane needed a pilot to control it, whereas a kite did not.

Mignet was openly hostile about the control of conventional aeroplanes in which aileron had to be corrected by rudder to achieve a balanced turn, and the fact that it was possible to cross these controls could lead to a spin and disaster. If one of these controls could be removed, he argued, it would be impossible to cross them and, voila, the problem would be solved~

Mignet observed that a kite does not possess ailerons yet is perfectly stable, only needing to be controlled in altitude and direction. Thus he decided that it was ailerons that he could afford to do without on his new design.

Using his earlier design, the conventional HM.8, Mignet made a brief study of aerodynamics - the centre of pressure, balance and controls. He dismissed bombastically the follies that had accumulated in the design of aircraft to date: 'Leave aviation to the aviators - let us go off on our own voyage of discovery.'

In a conventional aeroplane the pilot alters lift by varying the angle of incidence of the wing, using the elevators at the tail. This system, Mignet believed, introduced a delay in the controls and, just as a horse rider can establish a direct feel, or control, between himself and the horse, Mignet wanted a control system that gave immediacy to the aircraft's control.

If the tail (elevators) were fixed, he argued, and the main wing detached from the fuselage and allowed to pivot through direct control ]linkage with the control column, this immediacy of control could be achieved. Mignet realized the importance of the centre of pressure (Cp) in his system; it could only work if the pivot point of the wing were placed so that in all flight conditions the centre of pressure was behind it. This would ensure that the trailing edge of the wing was always trying to lift, creating a continuous 'feeling' on the control column and automatically tending toward a condition where the angle of incidence, and therefore the lift, decreased.

Mignet realised also the importance of the aerofoil shape required to stabilise the movement of the Cp, and his new aerofoil had an upturned trailing edge. Any increase in incidence would increase the pull on the control column. This would be a force instantly recognisable to the pilot; in Mignet's terms: "He has a living wing'.

Landing with the new wing presented problems. The conventional arrangement of the HM.8 meant that, upon cutting the engine for a landing, the aircraft was still going too fast, necessitating a pull back on the stick to increase the wing's incidence. At 30 mph, still flying, Mignet pulled back still further with the aeroplane dropping alarmingly to the ground. The craft had run out of lift and stalled - displaying, in fact, the characteristics common to conventional aircraft when flown inaccurately.

Mignet considered the installation of a Handley Page Slot on the leading edge to overcome this condition. He eventually viewed this unfavourably because it worked best at an exaggerated angle of incidence - not a good attitude for a landing or take-off. His solution used the slot principle, but in such a way that it was unrecognisable.

One has to admire the Mignet solution to the design problem. It was simple and logical yet totally revolutionary. What would happen if a trailing edge of a wing from which the air was about to 'unstick' was positioned close to another wing that was in an unstalled state? Mignet figured that, given the pressure on the underside of the front wing and depression on the upper surface of the rear wing, air would rush between the gap. This gap would act as a venturi and would help further in pulling down the air leaving the front wing, delaying the breakaway and in so doing delaying the stall.

Mignet had arrived at a kind of biplane with wings of the utmost stagger, almost a tandem, but not really one or the other. Mignet claimed that this arrangement's major attribute was that if the rear wing lifted too much and the front wing would not lift at all, then the craft would fall forward and dive. A real stall would be impossible.

So the configuration of the HM.14 Pou du Ciel came to be. Mignet summed up his findings in Le Sport de lAir. 'The slot or gap effect gives the rear wing progressive independence of the front. A tailplane becomes superfluous. Our tandem biplane, which is neither thing in fact, becomes a single wing with a gap . . . a tailless plane.'

This philosophy Mignet termed Aerotechnique' in Le Sport de lAir going on to discuss fore-and-aft balance, sudden loads, lateral balance, lateral control, defects and finally the art of turning. To turn the Flea the pilot simply moved the control column to the side, the aeroplane taking up its own bank proportional to the amount of rudder. 'Whether one turns wide or short, whether one is a new or experienced pilot, one turns correctly because ONE CANNOT TURN OTHERWISE!' Pleased with his conclusions, Mignet often highlighted his final sentences with block capitals.

His progression through what must have been virgin territory for many of his readers was presented in an easily readable and understandable manner - though his conclusions were not always the result of classical logic. His style was infectious, bringing the reader to peaks at crucial conclusions and concreting ideas as he progressed through the book. He broke the barrier protecting the world of aviation from the man in the street with statements such as '. . . all the work of pilotage is entrusted to the hand.' 'The technique of flight control is that of a bird.' 'The Flea is a kite with an auxiliary engine. Isn't that another kind of flying?'

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He cut through jargon and mystique with ease, making flying seem a natural extension of human exercise. His affable style and new ideas uncorked the champagne bottle. His formula for a lightweight 'aenal motorcycle' that anyone could fly was what many handymen with a latent interest in aviation had been waiting for.

Having got the theories onto paper through Les Ailes and his book, it was time for Mignet to become practically involved, both in the new craft's design and its test flying. He described the Flea as the grown-up brother of the HM.8, the HM.14 using the same method of construction as the HM.8 for both the wings and the fuselage. The Flea benefited from the considerable feedback from HM.8 builders and Mignet's own experiences.

The HM.14 design confommed to two chief principles: to be safe and easy to pilot to be small, simple, solid and practical -it should be possible to build a Flea in a 13 foot (4 m) long room.

Wing span for each of the Flea's wings was initially 13 ft (4 m) but improved efficiency was sought and the forewing's span became 16 ft 5 in (5 m) and later 19 ft 6 in (6 m). Simplicity of construction without sacrificing strength was claimed for the wings. The wings were basically similar with a single box spar, and most of the same ribs, the whole being covered with varnished fabric. There were no ailerons, no slots, no elevators, no complicated movements, no hidden cables, levers or mechanisms. Mignet claimed that both of these very simple structures could be built in eight days. He did not, however, state how many working hours per day would have to be devoted to achieve this target.

The fuselage concept was identical basically an empty box. His dislike of conventional aircraft and their enclosed cockpits, and the need for simplicity, gave rise to the 'flying armchair' style of cockpit, giving excellent visibility in all directions, including forward.

On to this structure was assembled the control column and linkages to the front wing and rudder, the axle and wheels and of course the engine and its accessories. With the exception of the lower portion of the control column, all mechanisms were readily accessible. Mignet anticipated a favourable reaction from airworthiness authorities because of this 'open' construction -no cowlings to hide the engine, no ailerons and their controls. If the wing covering were transparent this would be the final accolade!

The cardinal aspect of 'security of construction' was dealt with quickly, Mignet deducing that being of simple design it could be made so strong that only 'a real crash would smash it to pieces'. Mignet supports this analysis with the survival of his prototype Flea during his wintertime experimentations in the Bois de Bouleaux.

Materials were given little attention, wood and mild steel being readily accessible to the amateur. Today's guardians of the homebuilder, the Experimental Aircraft Association (IJSA), the Popular Flying Association (U10 and the Reseau du Sport de l'Air (France), would be horrified. All materials now have to come from approved suppliers whose stocks are regularly checked and inspected.

Though the concept of the 'Flea' was by now crystallized in Mignet's mind, there was still a long way, and a number of important intermediate designs, to go before its materialization as the HM.14.

These were the steps to the Flea, paving the way for the crystallization of Mignet's thoughts and ideas. On 10 August 1933 he started to build his prototype HM.14. Exactly one month later this first 'real' Flea took to the air from the Bois de Bouleaux on its maiden flight. From this moment on the frustrations and elations in mastering the Flea, together with the fine-tuning of the basic design were recorded in Mignet's diary. Extracts from his flying diary appear separately

Into print

'I have the right to write a book.' Mignet's construction diary closes with this claim. This book was to be his second book entitled Le Sport de lAir published in France in November 1934 a year after his experiments in the Bois de Bouleaux had been concluded and with some ten hours' flying under the HM.14's wheels.

Prior to this Mignet had gone into print in September 1934 in the French aviation magazine Les Ailes, writing an article entitled Le Pou du Ciel. Readers were already familiar with the name Mignet as he had made several contributions to it, including the famous article LAviation de le mateurestelle une Possibilite?

No sooner had Le Sport de lAir been published than further exposure of the Flea to the world of aviation was assured by its display at the 14eme Salon de lAeronautique au Grand Palais held between 16 November and 2 December 1934. The real test came a week later when Mignet organised the first public flying demonstration of his HM.14 at Orly Airport, then an all-grass airfield.

Painted red and white and powered by a 17 hp Aubier et Dunne the HM.14 was 'hopped and flown all around the airfield'. These demonstration flights certainly helped to capture the public's imagination, and Mignet was carried shoulder high in triumph by one ecstatic group who witnessed his flying. The weather for this flying was very poor with winds of 20 mph, gusting to 40 mph. Les liles for 13 December reported the event, stating that Mignet was not put out by the conditions, making one landing with the engine cut.

Both Les Ailes and 7Le Aeroplane referred to 'the joke' that neither Mignet nor his aeroplanes were licensed by the French authonties. 77Le Aeroplane had reported on the Flea a few months earlier in their Paris Salon edition noting that 'this machine warranted more serious attention than its obscure position in the Salon and curious appearance were likely to make for it'. Their edition of 13 March 1935 brought to the British aeronautical public their first detailed taste of the 'Sky-Louse' as the magazine christened the Flea.

The. Book, the Salon and the Orly demonstration had further opened the flood gates. By March 1935 popular gossip put the total number of Fleas already under construction at 500. As with every new craze there were equal amounts of hard fact and fiction. With the craze gathering momentum in France, Britain was rife with reports of all-metal Fleas, retractable undercarriage Fleas, acrobatic Fleas, night flying Fleas and family cabin versions of the Flea.

With so many Fleas under construction in France the Reseau des Amateurs) was formed for Flea builders to have a central organisation to look after and promote their interests. Henri and Annette toured the country visiting regional groupings of the RKA. Pictures taken in 1935 already show gatherings of two, three and sometimes four Fleas. All would be basically similar, often with different powerplants, but all perpetuating 'the joke': Flying without licences for either aeroplane or pilot.

 

 

 

 

On 13 August 1935 'the joke' invaded Britain. Mignet' piloting his Flea powered by a 17 hp Aubier et Dunne, crossed the English Channel from St. Inglevort to Lympne in 52 minutes. The invasion of Britain was to be achieved with the embodiment of French officialdom supporting a meeting of aircraft and aviators that were, strictly speaking, illegal.Mignet had flown in the face of authority by launching amateur aviation on a wide scale in France with the HM.63 and was set for even bigger things with the HM.14. Few people believed such a movement was possible, least of all those in the French administration. Mignet had earlier recommended builders of his designs to make sure there were no gendarInes around when wanting to fly. If forced to land away from home there was a real possibility of the pilot ending up in court

At Orly 'the joke' presented the authorities with a fait accompli and virtually forced them to change their attitudes. The Ministry of Air backed down, but not without considerable resentment from many quarters. Around 15,000 spectators turned up at Orly to see the Fleas, proof - if it were needed - of the wide public appeal that the Flea had created in such a relatively short period of time. Nine Fleas attended the event, including Mignet's prototype, now fitted with a 27 hp Aubier et Dunne.

First photo in was Wayne Cutrell.. Neato Wayne. Looks like that little motor is just asking to be electrified!

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