FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1928
1928 - 0978.PDF
OCTOBER 18, 1928 m m m m The Dornier " Super-Wai " : The power piant consists of four " Jupiters." The boat hull is of the flat-sided type, and shows a perfectly straight sheer line. There is a slight Vee bottom ahead of the step, but far less pronounced than that found on all modern British flying-boats. Aft of the step, which is located farther aft than is the main step in British flying-boats, the main hull bottom slopes up to the sternpost, and built oa to it is a form of rear step which is not, however, of the same but of far smaller beam than the main hull at this point. This second step, or keel, terminates at the rear in a vertical knife edge, to which is hinged a water rudder. Lateral stability is obtained by wing stumps growing out of the chosen in any haphazard manner. The boat deck is but slightly cambered, so that it is possible, when the machine is on the water, to walk about " on deck " in comfort. The shape of the whole hull is more like that of a modern high- speed motor boat, and has many advantages for handling on the water. How the drag coefficient compares with that of representative British flying-boat hulls we have no means of knowing, but in view of the much more nearly stream-line form of our boats, even to the fairing-in of the steps, it seems likely that the Dornier type of hull must have a greater drag coefficient than ours. [" FLIGHT " Sketches THE DORNIER " SUPER WAL " f Sketches showing forms of Dornier metal wing-spar construction. sides of the hull. Exactly how porpoising is avoided with such an arrangement of steps is not clear, but films of the machine taking off indicate no tendency to porpoise, so that presumably this vice can be successfully cured by other means than those generally employed in England. It is to be supposed that the aft step or keel structure serves to reduce the shock on alighting, as the relatively flat vee of the main hull bottom would not appear to English eyes capable of doing so in anything of a rough sea. The Domier firm has had carried out a very large number of tank tests on models, and it is not likely that the present form has been [" FLIGHT " Sketch AN UNUSUAL FORM OF RUDDER BALANCE : On the Dornier " Super-Wai " separate surfaces, unstably hinged, are made to facilitate the work of operating the rudder. Whether the wing stump type of side float is better or worse than the separate wing float is open to discussion. Set as the wing stumps are in the Dornier machines at a large aijgle of incidence (necessitated by considerations of water performance), one would expect them to carry a considerable amount of weight, and while they may, as is sometimes claimed for them (although we have not seen the claim made by Herr Dornier himself), " carry their own weight " in flight, the induced drag must be fairly great in view of the 908
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
