Registered 20 August 1926. Later modified to a Model LéO 213 and operated by Air France, formed by the merger of Air Union with other French airlines -7 Oct.1933. Shortly after departing Le Bourget on a mail flight to Croydon on 16 Nov.1933 the port engine caught fire. The two crew members bailed out and the abandoned aircraft stalled and crashed into an electricity pole and a factory roof before bursting into flames in a tributary of the Avelon River, near Beauvais. Both pilots were uninjured but the aircraft and its cargo of over a ton of mail were all destroyed.

First flown in August 1926, the LéO 21 was a large airliner based on the LéO 20 night bomber. It could carry 18 pax but on Air Union's Rayon d'Or / Golden Ray service from Paris to London it seated twelve, with a galley occupying the nose. The second prototype, designated LéO 212, is seen departing in a national air rally to the Auvergne, flown by Air Union chief pilot Robert Bajac.