Flight, December 1930
The PARIS AERO SHOW
THE GERMAN EXHIBITS
GERMANY is represented, in the Grand Nef, by a single machine, the new Dornier Do. S. On the general German stand, under the gallery, are shown two complete machines: one of the BFW monoplanes,
with “Argus” engine, which took part in the International Touring Competition, and a Junkers "Junior" fitted with Armstrong Siddeley "Genet" engine. The Junkers "Junior" is exhibited most effectively, part of the covering being removed to show the internal structure. In addition to these two full-size machines, there is a very large scale model of a Klemm, and a number of smaller models of Rohrbach, Heinkel and Focke-Wulf machines. The latter is a model of the new "Ente," a detailed description of which will be given in FLIGHT shortly.
The Dornier Do. S is, in a general way, similar to the familiar Dornier "Wal" flying boats, but is somewhat larger, although not nearly as large as the Do. X. What, apparently. Dr. Dornier has done is to enlarge his machine, but keeping the number of the crew the same, so that the weight of crew represents a smaller proportion of the disposable load. Certain changes are also to be noted in the wing bracing. Each wing is braced by a single strut of metal, and the structure stabilised in torsion by wires in the planes of the front and rear spars. On top of the wing, wire bracing to the engine mountings is in a single plane only, that of the front spars. Short wing stumps springing from the boat hull provide lateral stability on the water, and these stumps are further made to assist the bracing of the wings and the support of the engines by running two struts on each side from the stumps to the wing spars, under the engine mountings. It is to be assumed that this arrangement results in a certain saving in weight, as compared with earlier Dornier "Wal" types.
Structurally, the Do. S follows fairly closely previous Dornier practice. The boat hull, as well as the wing structure is duralumin planked, with smooth plates. The four Hispano-Suiza engines are arranged in two tandem pairs, and nose radiators serve to cool both forward and rear engines. Each radiator is divided into two, so that presumably the two sets of water system in each nacelle are independent of each other. The hull is of usual Dornier single-stepped form, with a pronounced vee bottom forward, a fairly flat step, and a vee-bottom aft of the step. At the stern there is a water rudder operated by the pilot through a separate lever, independent of the air controls.
The internal accommodation is divided into two cabins for passengers, of which the forward, near the bows, has seats for 12 passengers, and the aft cabin seats 10. A kitchen, &c, is provided, and the quarters of the crew are kept quite separate from those of the passengers, being contained in the superstructure on the deck of the hull, ahead of the wing. The forward portion of this superstructure, or "bridge" contains the pilots' cab, seats being arranged side by side, and with dual controls. Behind that comes the navigator's compartment, the engine control room, and the wireless cabin.
No figures are available relating to weights and performances, but the main dimensions of the Do. S are: length, 25 m. 75 (84 ft. 5 in.); wing span, 31 m. (101 ft. 7 in.); wing area, 209 m.1 (2,250 sq. ft).