On 10th January 1935, the French six engine, double deck long-range flying boat Latécoère 521, performed its first flight.
The Latécoère 521 was one of many seaplanes designed and built by Pierre-Georges Latécoère, the French aviation pioneer and the founder of aeronautical industry in Toulouse.
Before the Great War, the Latécoère company was manufacturing trams and freight wagons. In 1917, he invested in several factories to be established in the region to produce ammunition and military equipment, including aircraft. His first aviation development, designated Latécoère 1 (the official designation often being shortened as just Laté) was a concept of two-seat fighter, but it never went beyond the design stage.
Nevertheless, in the same year Latécoère received two orders from the French government to license manufacture of Breguet 14 fighter aircraft and Salmson 2 reconnaissance aeroplanes, officially designated Latécoère 1 and 2, respectively. Especially important was the second of the aforementioned contracts, worth 25 million francs and aimed to build 1,000 examples of the aircraft.
After the war, Latécoère continued to manufacture both types of the aircraft and developed their passenger variants, commonly known as Limousine Salmson-Latécoère and Limousine Breguet-Latécoère. In 1918, Latécoère also established his own aviation company, officially named Société des lignes Latécoère (Latécoère Lines Company) but usually referred to as Lignes aeriennes Latécoère (Latécoère airlines) or just La ligne (The Line).
In 1919, Latécoère introduced his first aircraft prototype, Latécoère 3, a two-seat, single engine biplane for passenger and postal transportation. Then, he continued with development of several other prototypes of passenger and military aeroplanes but what finally earned him fame and made the Latécoère company well known all over the world, were seaplanes and flying boats.
In 1929, the Latécoère company began with development of a long-range passenger flying boat, able to operate on transatlantic routes. Latécoère 520, as the project was initially designated, was a huge sesquiplane featuring a double-deck hull with seats for eighty passengers and equipped with four engines in push-pull, tandem configuration.
Over the next few years, the Latécoère´s project evaluated into the six-engine, double deck flying boat which offered a luxury travel conditions for seventy-two passengers, designated Latécoère 521. On 10th January 1935, prototype of the aircraft performed the first flight, with the company test pilot Pierre Crespy at its control.
The Latécoère 521 was also the sesquiplane and was powered by six Hispano-Suiza 12Ydrs powerplants, each capable of 890 hp. The four inboard engines were, similar to the original design, mounted in push-pull, tandem sets, with two additional outboard powerplants in pull configuration.
The aircraft featured the maximum take-off weight of 37,000 tonnes (later increased to 40,000 tonnes), 49.3 m wingspan, as well as length of 31.62 metres and height increasing 9 metres. At the time of its maiden flight, the Latécoère 521 was the biggest aircraft ever built in France, the first of giant flying boats developed by Pierre-Georges Latécoère, as well as one of the first projects of the giant passenger transatlantic aeroplanes. It still remains the eleventh largest flying boat in history of aviation.
The prototype of aircraft was registered F-NORD and named ´Lieutenant de Vaisseau Paris´ in honour of the famous, record-setting French pilot of the era, Paulin Louis Jérôme Paris, who died in 1934. Yet in 1935, the Latécoère 521 began its demonstration tour to Dakar, then Natal, the French Antilles and Florida. There, the French flying boat was damaged by a hurricane and shipped back to France for repairs.
After repair, the Latécoère 521 was acquired by Air France Transatlantique and began its service as experimental aircraft. Although the flying boat crossed the Atlantic several times, it never entered regular passenger service and, reportedly, never carried a paying traveller on board. Interesting fact is that, during transatlantic flights, the aeroplane capacity was reduced to only about thirty passengers (offering even more luxurious conditions for travel), while maximum capacity was used usually with shorter flights to Africa and Mediterranean.
The Latécoère 521 set several world records in payload and flight endurance categories. In addition, the aircraft set the speed record for the fastest, non-stop crossing of the Atlantic, as well as completed a flight from New York City to Biscarrosse with average speed of 206 kph, with one engine out of service for a distance of 2,300 km (out of 5,875 km of total distance).
In 1939, the second, upgraded example of the aeroplane entered operational service. The new flying boat was designated Latécoère 522 and named ´Ville de Saint Pierre´. In addition, three maritime patrol aircraft designated Latécoère 523 and named Algol, Aldébaran and Altair, were built and entered into service with the French naval aviation shortly before the war.
At the outbreak of the World War II, both the Latécoère 521 and 522 were militarised and converted into maritime patrol aircraft. All the five examples of the aeroplane served with the French Navy and then were taken over and operated by the Vichy forces. In 1944, all the flying boats of the Latécoère 520 family were destroyed by the retreating Axis forces.
All photos: NACA Aircraft Circular No. 202, 1936, Public Domain
