Newsgroups: rec.aviation.homebuilt
Subject: Re: Flying Flea info wanted
From: mark@nezsdc.icl.co.nz (Mark Hutching)
Date: Tue, 15 Dec 92 03:15:08 GMT
Organization: Fujitsu New Zealand

In article <1992Dec8.233545.23487@pasteur.Berkeley.EDU> ron@etch-eshop.Berkeley.EDU (Ronald Viegelahn) writes:
> Hello netland:
>
> I'm looking for  some information (again). I just received the
>info pack from Falconair in Alberta Cannada. The plane I got the info on
>is the HM290E (ultralight version). It's been nick-named the " Flying
>Flea ". 
>
> It's a staggared wing design using the aft most wing as a lifting
>stabilizer. The front, Higher mounted wing pivots and this is how
>up/down motion is controlled. Kind of like a canard aircraft in my
>view point.
>
>				Ron Viegelahn
>				ron@etcheshop.Berkeley.EDU


  The Flying Flea was originally designed (about 1932) by a Frenchman,
Henri Mignet, hence the name HM290. The original was HM14, his 14th 
design. His ideal was to design an aeroplane that anyone (?) would be able
to build and TEACH themselves to fly in. He had trouble learning to fly the 
"conventional" way, i.e. hands controlling pitch and roll, feet keeping it
all balanced, so designed a plane that was to be simpler to fly.

  The Flea had no roll control, relying on exaggerated eliptical dihedral
and a low centre of gravity to provide lateral stability and the necessary
bank in turns, which were initiated by moving the huge rudder. The rudder
and forward wing pitch were controlled from a single stick in the cockpit,
there being no pedals. This stick and the throttle were it as far as
controls went.
  The front wing was a pivoted on a pylon and mounted a foot or so 
higher than the rear wing. The wings were seperated longitudinally by
a gap of about 2 feet, and the pilot sat between them, looking forward
under the front wing and trying to see around the single cylinder,
upright, converted motorcycle engine.
  The front wing incidence was increased by pulling back on the stick,
which pulled a wire attached to the trailing edge. Relaxing stick 
pressure allowed a large spring running between the leading edge and
the engine mount to decrease the wing incidence again to pitch the
nose down.

  This control method, while simple, led to the designs failure. 

  One report I have read on the Flea's problem goes like this:
Pulling back on the stick increased the front wing incidence and 
therefore lift. If, however, a pilot had allowed the nose to get too 
far down and the speed too high, pulling the front wing trailing edge
down also decreased the gap between the two wings to such an extent
that the "slot" effect became significant. The resultant increase
in air speed over the top surface of the REAR wing caused a
corresponding increase in that wings lift also. Equals - no pitch up
and continued, usually rapid, descent.

  Another report stated that RAE Farnborough tested it in the wind
tunnel and found that if the front wing's incidence was allowed to 
get to -15 degrees, the situation became irrecoverable. An ever 
steeper dive developed.

  Whatever the reason, the original Flying Flea killed many, many
potential aviators and was eventually banned in Britain. Redesigned
, and safe, Fleas eventually reappeared. Model Flying Fleas can exhibit
the same behaviour as the full size and the way to cure them is to 
link the top wing trailing edge to the back wing leading so that the
gap remains the same.
  Lastly, the original name in French is "Pou du Ciel" or Louse of
the Sky, mis interpreted as Flea ( "Pouce" ).

  The above has been gleaned from Bill Gunston's "Plane Speaking" and
from dusty memories. I also saw a replica a few weeks ago, built from
copies of the original plans. As a first time contributor I shall be 
interested in any reactions provoked.
Newsgroups: rec.aviation.homebuilt