S.A.M. #51: Dewoitine Trimotors

This Saturday, our Air Mail is here to remind you about the French long-range civil aircraft - probably not as famous as their German and Italian contemporaries but nevertheless iconic.

In early 1930s, Emile Dewoitine, already a prominent aircraft designer, changed his concept from high- to low-wing. He was keen about the range of his machines. The single-engined D.33 Trait d'Union record plane (below) was the first step in this direction, while for the commercial aircraft the three-engined configuration was chosen.

In early 1933, the D.332 came up, and on July 11th this year had its maiden flight under the control of test pilot Marcel Doret. It was an all-metal cantilever construction, the fixed main undercarriage had 'trousers-shaped' cowlings. The strutted tailplane was the typical Dewoitine trademark. Pilot and co-pilot sat side-by-side, with radio operator's station directly behind them.

The cabin for eight passengers was very spacious, with electric heating and ventilation. For night flights, the seats could be converted into beds. The aircraft was powered by the three Hispano-Suiza 9V radials (a license-built version of the Wright Cyclone).

On September 7th, 1933, the new transport aircraft set a world record flying the 1,000 km distance carrying a payload of 2 tons at a speed of 259.56 km/h. The D.332, baptized Emeraude, was destined for a direct connection to Saigon, French Indochina. On December 21st, 1933, it flew to this destination, reaching Saigon on December 28th.

On its way back, at a distance of not more than 400 km from Le Bourget, the plane crashed in the Monts du Morvan near Corbigny. Ten people aboard the plane were killed, including Maurice Nogues (one of the aviation pioneers, WWI hero, former Air Orient chief pilot and acting Air France Operations Director) and Pierre Pasquier, the General Governor of the French Indochina. The cause of the crash was disorientation, most probably due to heavy icing in a snowstorm.

Despite this disaster, the Air France ordered three airframes of the Dewoitine trimotor with an enhanced cabin. The new version, designated D.333 (above and below), was designed for ten passengers and had had an increased payload capacity. For several years, these machines served on the route between Toulouse and Dakar.

One, Antares, was lost in October 1937, the others from 1938 flew in South America, used for Buenos Aires-Natal passenger service. These two, baptized F-ANQB Cassiopee and F-ANQE Altair, in 1943 were bought from  by the Argentine government and on 17th January, 1944, were officially immatriculated under No. 172 and 173 to the 2nd Squadron of the Transport Group of the Argentinian Air Force. No. 172 was grounded in July 1946, while No. 173 continued serving until 1947.

After the prototype of the Dewoitine D.338 (above) had flown in 1936, the Air France ordered 30 serial samples. Fuselage and wings were slightly increased, the main undercarriage was retractable. The airliner could carry 22 passengers on short-distance flights and serve as a 12-passengers sleeper on longer distances.

Powered by the three Hispano-Suiza 16/17V (650hp each), the aircraft reached a maximum speed of 301 km/h and a cruising speed of 260 km/h.

The type earned a good reputation for reliability, and during WWII, a number of 338's were employed by Lignes Aériennes Militaires (LAM) in the French overseas territories, used for Beirut-Brazzavile transport service. Some were requisitioned by the German forces, serving with Deutsche Lufthansa. After the war, 9 aircraft were still airworthy and flew on the route Paris-Nice for several months.

The D.338 by Lucio Perinotto...

and Shigeo Koike

In 1939, the D.342 appeared, a single sample with improved streamlining and three Gnome-Rhone 14N radials of 915 hp. It had a passenger capacity of 24. In 1942, it was delivered to Air France under the designation F-ARIZ. The war prevented a further development. It crashed on 27 Sept. 1942 at Ameur el Ain, Algeria.

Sources: Romantic Technofreak @ Warbirds Forum, Avions Civils