The AV.31 was a giant transport plane with a wingspan of 295 feet (90 meters) and a take-off weight of 200 tonnes. All the passengers, fuel, and engines were situated in the wing, reducing the cockpit to a small nacelle in front of the wing. The passenger cabin, fully submerged in the wing, was 27 m long and 9 m wide, and could accommodate a variety of layouts. A bomber version was proposed as the AV.32.[1]
To test the flight characteristics of the AV.31, Charles Fauvel proposed a 1/3 scale flying model, which would have been propelled by four 250 hp "Béarn" engines and had a span of 104 feet (32 m), a take-off weight of 8150 kg, and maximum speed of 354 km/h.
The AV.31, despite its great potential, did not leave the drawing board.