The prototype was a low-wing cantilever monoplane with a fixed tailwheel landing gear and powered by a 180 hp (130 kW) Mathis 8G.20 inverted V8 engine.

The engine was replaced with a German war-surplus 240 hp (180 kW) Argus As 10 and the prototype flew again in November 1949 as the MS.731.

Seventy of the French Air Force aircraft were fitted with machine guns for gunnery training and some of these were later converted for counter-insurgency operations (and re-designated MS.733A) for use in Algeria.

For this reason, it was often used for navigation training as it was far cheaper to operate than the twin-engine designs commonly used for that task.

Since retirement by the French military services, several Alcyons have been restored to flying condition in France by private pilot owners and groups.