The Ahrens AR 404
was a prototype US civil transport aircraft first flown in 1976
, a high-wing monoplane
powered by four turboprop
engines. In order to facilitate the loading and unloading of cargo, the fuselage
was of constant rectangular section along almost its entire length, the main undercarriage
was retracted into sponsons
on the fuselage sides, and the tail included a loading ramp. As a regional airliner, the AR 404 was designed to carry 30 passengers, or in its cargo configuration, to accommodate four standard D3 freight containers.
Ahrens secured a production deal with the government of Puerto Rico, which agreed to finance the type certification of the aircraft if Ahrens would establish its production facilities there. The first production aircraft was built and flown there in 1979, but no more were constructed after financing was withdrawn.