The Late 521 in its original form, at Biscarrosse at the time of its first flight in early 1935.

Looking like Noah’s Ark, the hull of the Late 522 Ville de Saint-Pierre on its four-day journey from Anglet, near Bayonne, to Biscarrosse in March 1939.

The Late 521 shortly after launching from its slipway in early 1935.

A rare and revealing shot of the Late 521 in flight during 1935, showing the very broad-chord wing.

The reconstructed Late 521 under tow at Biscarrosse. Painted light blue with a white rudder, the flying-boat carries the Air France Transatlantique emblem below the flightdeck window - a white seagull over a round blue shield representing the North Atlantic, with the European, African and American continents in ochre.

The Late 521 in its original form, at Biscarrosse at the time of its first flight in early 1935.

Another rare view of the Late 521 in flight in its earlier form in 1935.

The Late 521 being salvaged after it sank during the storm at Pensacola on the night of January 15-16, 1936. It was rebuilt, and went on to complete a series of technical proving and survey flights on the North Atlantic in 1938-39.