The FP-404 was designed by Fisher Aircraft in the United States in 1984 and was the company's first design that was too heavy for the US FAR 103 Ultralight Vehicles category, with the category's maximum 2540NaN0 empty weight. The 404's standard empty weight is 2750NaN0 when equipped with a two-stroke 500NaN0 Rotax 503 engine, putting it into the US experimental-amateur-built category, although it qualifies as an ultralight in other countries, such as Canada. The design goal was to provide a nostalgic aircraft reminiscent of the biplanes of the 1930s, as the company explains "The FP-404 represents a reborn era in airborne adventure. This bi-plane aircraft is a throw-back to seat-of-the-pants flying, complete with minimal instruments and bare-necessity controls."
The construction of the FP-404 is similar to the Fisher FP-202 Koala. The aircraft's structure is entirely made from wood, with the wooden fuselage built from wood strips arranged in a geodesic form, resulting in a very strong and light aircraft with redundant load paths. Both the wings and fuselage are covered with doped aircraft fabric. The wings are strut-braced with both interplane struts and cabane struts. The aircraft has no flaps. The company claims it takes an amateur builder 500 hours to build the FP-404, "using normal household tools".
Early versions of the FP-404 were equipped with the 280NaN0 Rotax 277 in an attempt to keep the aircraft under the US FAR 103 Ultralight Vehicles weight limit but the aircraft was found to be under-powered due to its short wing span and high-drag configuration. Heavier engines, like the 400NaN0 Rotax 447 and 500NaN0 Rotax 503 engines provided adequate power but put the 404 over the category weight limit. These models were designated as the Fisher 404 EXP to show that they would not qualify for the FAR 103 weight limit.
By late 2004 over 350 FP-404s were flying.
Reviewer Andre Cliche said about the design:
