It was a high-wing monoplane with its four Gnôme et Rhône 9 Kdr radial engines mounted on the wings in tandem, tractor-pusher pairs.

The wing centre section, between the engines, had an all-metal internal structure and the forward part of the skin was also metal, replaced by fabric further aft.

The outer wing sections were slightly tapered on the leading edge only, with elliptical tips; they were entirely fabric-covered over a largely wooden structure, though the principal ribs were metal lattices.

These were mounted below the engines with four vertical spars per side and braced to the fuselage with a further pair running upwards and inwards.

After some modifications to engine cowlings, wings and tail it went to CEPANA at Saint-Raphaël, Var for trials in October 1933 and in November was converted, in less than four hours, into a landplane.

It was not well received and described as unfit for purpose: instabilities, high control loads and pitching on contact with the water were amongst the criticisms.

It seems to have handled better, but by now its maximum speed was seen as low; when the sole 550 was lost in October 1934, its port float struts collapsing on alighting, there was no enthusiasm for further development.