Flight, June 1924

THE THIRD INTERNATIONAL AERO SHOW AT PRAGUE
THE FRENCH EXHIBITS

DEWOITINE.

   THE Dewoitine exhibit is an all-metal parasol monoplane, type D.1, fitted with a 300-h.p. Hispano-Suiza engine, and intended for scouting work. Its fuselage is constructed entirely of duralumin, being built up of four main spars, and secondary struts, of semi-circular or U section. The covering is also of duralumin. A thick section semi-cantilever wing is employed, being supported in the centre a short distance above the fuselage by a short vertical panel, or enclosed cabane, while two pairs of struts extend from the lower longerons of the fuselage up to the wing spars at a point midway between the centre and the tips of the wings. The wings taper, both in thickness and chord, toward the tips, and the ailerons, which are unbalanced, are of high aspect ratio.
   The horizontal tail surface, which is comparatively small, is built up of two spars and two duralumin tubes which serve as ribs. Its angle of incidence can be varied during flight. The landing gear is of the V-type, of duralumin, carrying a divided duralumin axle. It is provided with a patent shock-absorbing device. Two duralumin V's, and four tubes connected to the first truss of the fuselage, support the engine, which is fitted with a Letombe starter.
   Petrol is fed by two A.M. pumps, the petrol tank being located between the pilot's cockpit and the engine, from which it is separated by a duralumin bulkhead. The new 1924 Lamblin strut-radiators are fitted.
   This machine was purchased by the Minister for National Defence for Czecho-Slovakia.
   The principal characteristics of the Dewoitine are: Span, 11 500 m. (37 ft. 9 ins.); overall length, 7-550 m. (25 ft.); wing area, 20 m.2 (215-2 sq. ft.); weight of machine, empty, 820 kgs. (1,808 lbs.); useful load, 420 kgs. (924 lbs.); total weight, 1,240 kgs. (2,734 lbs.); wing loading. 62 kgs./sq. m. (12-7 lbs./sq. ft.); power loading, 4-150 kgs./h.p. (9-15 lbs./h.p.); speed, 250 km. per hour (155 m.p.h.); ceiling, 9,000 m. (29,700 ft.).

Flight, December 1924

The Paris Aero Show 1924

CONSTRUCTIONS AERONAUTIQUES E. DEWOITINE

   A COMPARATIVE newcomer to the French aircraft industry M. E. Dewoitine, whose experimental works and offices are now at Chatillon-sous-Bagneux (Seine), while the original works at Toulouse are devoted to quantity production, is rapidly gaining a leading position among French aircraft designers. Probably the first introduction of M. Dewoitine to readers of FLIGHT dates back to the 1920 Paris aero show, when a scale model of the Dewoitine twin-engined commercial monoplane was shown. Incidentally the same machine is, we understand, being produced as a night bomber. At this year's Paris Show M. Dewoitine is showing four machines, two of which are of the D.1 C.1 type, while the third is the D.7 light monoplane, and the fourth a large commercial monoplane.
   The machine with which hitherto M. Dewoitine has had the greatest success is the all-metal single-seater fighter monoplane, the D.1 C.1. Examples of this machine have been supplied to the French and to many foreign governments, and we learn that recently the Italian government has placed an order for 150 of these machines.
   The Dewoitine D.1 C.1 is a thick-wing strut-braced parasol monoplane built entirely of metal, and is fitted as standard with the 300 h.p. Hispano-Suiza engine. A slightly different version, fitted with French-built Bristol "Jupiter" engine is known as the D.9 C.1. The fuselage is of elliptical section and is built entirely of Duralumin, even to the covering. Bulkheads or formers of various built-up and channel sections provide the shape, and four main longerons, with a number of light stringers, complete the framework, which is afterwards covered with sheet Duralumin riveted to formers and longerons. At the show it was not possible to obtain sketches of the fuselage construction, as both the machines shown had their fuselages entirely covered. It is gathered, however, that the construction has been found in practice to be both strong and simple to manufacture. By way of proof of the strength of his machines, M. Dewoitine exhibits a machine of the D.1 C.1 type, which was overturned at full speed when the pilot had to land in a thick fog. So far as could be ascertained the only damage sustained was a bent rudder post and one or two holes in the fabric covering of the wing.
   The Dewoitine wing construction is, like that of the fuselage, entirely metallic, and the material used is Duralumin. The wing spars are of built-up box section, the sides of the spar being of channel section and the flanges flat strips, angle-sections being used in the four corners. Possibly this form of construction can be used satisfactorily with Duralumin, where one can work with considerably thicker strip, but in steel it would scarcely be found to be economical. The ribs are tubular, both as regards flanges and lattice bars, the joints being made by wrapping thin Duralumin plates around all the members to be joined, and rivetting through the whole with tubular rivets. The rib construction is, in fact, identical with that of S.E.C.M., who, we understand, build most of Dewoitine's machines (as, in fact, they appear to build the majority of the French all-Duralumin aeroplanes). The equipment is that usual in single-seater fighters, i.e., two synchronised machine-guns, with 800 rounds of ammunition for each.
   The main dimensions of the Dewoitine D.1 C.1 are: Length overall, 7-5 metres (24 ft. 7 ins.); height, 2-75 metres (9 ft. 1 in.); span, 11-5 metres (37 ft. 9 ins.); wing area 20 sq. metres (215 sq. ft.). The figures for weights, etc., are: Weight empty, 820 kgs. (1,800 lbs.); fuel and oil, 200 kgs. (440 lbs.); useful load (i.e., pilot, armament and instruments), 220 kgs. (485 lbs.); total loaded weight 1,240 kgs. (2,725 lbs.). Power loading, 9 lbs./h.p.; wing loading, 14 lbs./sq. ft. The maximum speed at ground level is 247 km./h. (154 1/2 m.p.h.); at 2,000 metres (6,560 ft.), 250 km./h. (156 m.p.h.). The climb to 5,000 metres occupies 15 mins. 6 secs. Practical ceiling, 8,500 metres (27,900 ft.). Landing speed, 80 km./h. (50 m.p.h.).
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