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The Flying Flea

The Flying Flea
PILOT - "JEAN-PIERRE LE BAM"

The Flying Flea family of aircraft was designed by French furniture The Flying Flea manufacturer HENRI MIGNET He had failed to be accepted as a military pilot and decided to build his own plane. Between 1931 and 1933 he built prototypes in Paris and tested them in a large field northeast of the city. He successfully flew the first successful model, HM-14, in September 10, 1933 and publicly demonstrated it in 1934.

He published the plans and building instructions in Le Sport de L'Air, a book published the same year. In 1935 it was translated into English and serialised in Practical Mechanics, prompting hundreds of people to build their own Flying Fleas.

Mignet's original H.M.8 prototype aircraft was powered by a 17hp (13kW) Aubier-Dunne 500 cc two stroke motorcycle engine with a chain drive providing a 2.5:1 reduction ratio. It had a wingspan of 19.5 feet (5.9m), a  length of 11.5 feet (3.5m) and a gross weight of 450 lb (204 kg).[5]. It had  a usable speed range of 25-62 mph (40-100 km/h)

Design
Mignet made the aircraft intentionally simple. Flying Flea is essentially a highly staggered biplane, which could almost be considered a tandem wing aircraft.

Built of wood and fabric, the original design was single-seater and had a two-axis control. The control system was very unconventional. The aircraft had a standard control stick. Fore and aft movement controlled the front wing's angle of attack, increasing and decreasing the lift of the wing. Because the front wing was located forward of the center of gravity, this would pitch the nose up and down.

Side to side movement of the stick controlled the large rudder. This produced a rolling motion because the wings both had substantial dihedral, through yaw-roll coupling. The rudder had to be quite large, not only to produce adequate roll, but also because the fuselage was very short, reducing the leverage of the rudder.

The Flying Flea, being a two axis aircraft, could not be landed or taken off in substantial crosswinds. This was not a big issue when the aircraft was designed because at that time aircraft were usually flown from large open fields allowing all take-offs and landings into wind.

Mignet claimed that anyone who could build a packing case and drive a car could fly a Flying Flea.

Variants
There have been more than 300 different models of the Flying Flea. Some of these are listed over leaf

Specifications (H.M. 290 Flying Flea)
Data from Plane and Pilot: 1978 Aircraft Directory

General characteristics
      bullet Crew: one pilot                                bullet Length: 14.0 ft (4.27 m)
      bullet Wingspan: 20.0 ft (6.1 m)              bullet Height: ()
      bullet Empty weight: 410 lb (186 kg)      bullet Max takeoff weight: 700 lb (317 kg)
      bullet Power plant: 1                                  bullet McCulloch, 72 hp (54 kW)

Performance
      bullet Maximum speed: 85 mph (138 km/h)           bullet Cruise speed: 80 mph (130 km/h)
      bullet Stall speed: 35 mph (57 km/h)                       bullet Range: 275 mi (446 km) at 8,000 ft (2,438 m)
      bullet Service ceiling: 16,400ft (7437 m)                 bullet Rate of climb: 600 ft/min (3.05 m/s)
      bullet Power/mass: 9.72 lb/hp (5.9 kg/kW)

Safety Concerns
In the early days many Fleas crashed when pilots could not recover from shallow dives, resulting in some deaths. As a result the Flying Fleas were grounded and even banned from flight permanently in some countries. [5]

When on approach to land, the pilot would push the stick forward to gain speed for the flare and landing. 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. The pilot's normal reaction would be to pull back on the stick. This action would increase the angle of attack on the front wing by lowering the trailing edge of the wing. Because the trailing edge of the front wing was close to the leading edge of the rear wing the front wing's downwash would accelerate the air over the rear wing and cause it to gain lift more quickly that the front wing, resulting in an ever increasing nose pitch-down and flight directly into the ground.

Mignet had not encountered this problem during his testing of his prototype because he could not afford a large horsepower engine. When builders started putting larger engines on them and expanding the flight envelope the wing interference problem surfaced.

The Royal Aircraft Establishment in the United Kingdom and the French Air Ministry conducted full-scale wind tunnel tests and discovered the problem. Their investigations resulted in changes to the airfoil used and the spacing of the wings to prevent aerodynamic interference. Later Mignet Flea designs incorporated these changes.

By 1939 there were many improved Flying Fleas in the air but the aircraft never completely overcame its dangerous reputation, Amateur Construction.

Shortly after the plans appeared in 1934, many enthusiasts in Europe and the USA began to build their own aircraft. In France there were at least 500 completed. The average cost of materials was then $350.

Modern aircraft enthusiasts have continued to build their own aircraft and vary the original HM.14 design and its derivatives over the years, and outside the UK, they are successfully flown in countries like Australia. French enthusiasts, for example, hold an annual meeting every June.