FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1927
1927 - 0739.PDF
SEPTEMBER 29, 1927 GERMANY REVIVES "TAIL-FIRST" MACHINE Focke-Wulf 19 Passes its Preliminary Tests Successfully IT is a somewhat curious fact that modern times should see a reversal to the type of aeroplane which first left the ground in controlled flight, and that, by making full use of modern aerodynamic knowledge, this type, which was abandoned back in the childhood of aviation, should now be proved possessed of certain very marked advantages as compared with the type that has supplanted the original to the entire extinc- tion of the latter. It will possibly be news to those of our readers whose interest in aviation is of fairlv recent date to learn that the principle was used in the very earliest aeroplanes. Thus M. Santos Dumont used a machine of this type for his prize- winning flight of 1906. This machine had biplane front elevator as well as biplane main wings. Owing to the fact that in those days the action of the front elevator was imper- fectly understood, the machines were unstable fore and aft, and the tail-in-front arrangement gave way for the tail- behind system as it is used to-day. Actually the tail-first arrangement is capable of giving excellent fore and aft stability, provided certain precautions are taken. When, THE FOCKE-WULF " ENTE Three-quarter front view. Note the negative angle of incidence when thefront wheel is on the ground. first machine to fly under proper control was of the " tail- first " type. Commencing with the very early Wright gliders, the " tail-first " principle was adopted, and the first power-driven aeroplanes built and flown by the Wright Brothers were of this type. That is to say, the single engine drove tvvo " pusher " airscrews via a chain transmission. A narrow outrigger or girder carried two vertical rudders placed side by side and but a small distance apart. The elevator was mounted ahead of the main planes on another outrigger, the pilot sitting on the leading edge of the lower main plane. The early machines were somewhat tricky to fly, and it was not long before the elevator was transferred to the back of the machine. In France also the " tail-first " however, we come to directional stability and control the matter is less favourable, and the " Canard " type, as it used to be called in France, or " Ente " as it is termed in Germany, suffers from certain serious drawbacks. Before referring to these it may be of interest to examine briefly how the " Canard " or " Ente " obtains its longitudinal stability. It is, of course, well-known that an aeroplane wing reaches a certain maximum lift at some particular angle of incidence, the angle depending partly on the wing section used. If that angle is exceeded the lift begins to fall off, rapidly with some wing sections, less suddenly with others. It is this funda- mental principle which is made use of in the tail-first wing arrangement. It will be seen that if the same wing section THE FOCKE-WULF " ENTE ' Three-quarter rear view. To get the side areas correct, a very large fin isnecessary. 679
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
