Breslau EE 11 "Schlesien in Not"
Type
 
Dimensions
span 18,0 m, wing area 15,8 m2, aspect ratio 20,5 max. chord 1,3 m, at tip 0,3 m,
Weights
empty 133 kg, wing load 13,6 kg/m2
Performance
 
Type
Werk.Nr
Registration
History
     
Designed by Helmut Lindner in 1931. Göttingen 527 profile.
One of the very few machines which were of entirely new design at the 1931 Rhön Meeting was the "Schligh-per- formance sailplane which was to be entered for the first time in esien in Not" which had been built by the MarchoSilesia Academic Flying Society of Breslau, This machine has several features of interest and therefore readers are likley to find this description of it which has been specially translated from Flugsport , Oct. 14 by Dr.   I. E. Slater, well worth reading.
During the  "construction evenings " of the last winter term, we undertook the construction of a new hthe 1931 Rhön contest. Our underlying idea was that our. society should not spend all its endeavours upon the spoiling side of aviation, but that its programme should at the same time include work of the nature of scientific research.
Thus the building of a well-tried type from bought drawings, though no doubt the best plan for many groups, did not suit our purpose. In the case of the Oberschlesien (Type E.E. 7.), the use of a high aspect-ratio had given good results; we resolved therefore to continue work upon the same lines.
So we decided to build a machine to my design E.E.11. In this I retained the chief features of the Oberschlesien as regards the design and its execution, though it is true I made substantial alterations.
The single-spar wing is composed of a middle section of 2m. length and outer portions of 8m. each.  
The EE 11 could be erected by three men in 4 minutes. The aielerons were connected automatically. A very strong  box construction in the nose protected the pilot
The middle section is braced by A-struts and remains permanently mounted on the fuselage. The outer portions of the wing are secured to the middle section by 2 conical bolts at the main spar and 1 bolt at the leading-edge spar.
The aileron connecting levers in the middle section and those in the outer portions rotate about a common axis without sliding over each other, and clasp one another automatically when the outer wings are being attached.
Assembly is thus very simple, because the bolts securing the middle section to the fuselage, those for the struts and those for the aileron connections to the fuselage need not be undone at all, except when making repairs.
The ribs are at intervals of 320 mm. In the tension- resisting leading edge, the outer grain of the plywood runs perpendicularly to the spar.
The fuselage is built up on a strong box spar, which protects against collapse of the cockpit, carries the forward and main frames, and transmits the landing shock of the struts to the skid through 2 rubber buffers. Towards the tail, this box-spar is continued Into a specially strong keel-piece, which protects the tail from being either pushed in or torn out, and so takes the place of a cradle during construction.
The fuselage has an elliptical cross-section and is continued into a vertical stabilising fin. which in its turn carries a short horizontal fin. This elevator fin is situated about 0.7m. above ground level, so that it is endangered as little as possible by ground obstructions during taking-off and landing.   The control mechanism is designed in such a way that the control surfaces can be mounted in quick time without bothering with bolts, and that no control lever shall lie outside the fuselage.
It has been my endeavour in this design to keep the weight as low as possible consistent with the regulations as to structural strength and with small resistance of the struts, in order that the low-sinking rate resulting from a good aspect ratio should not be compromised by too high a wing loading. (lt is possible, to achieve a still further saving of weight without loss of strength, even with the materials which are in general use to-day. The flights in weak thermic up-currents made during the last Rhön contest have shown the need for such aircraft, whose low sinking-rate depends, not upon unusually light wingloading, but upon the beneficial reduction of drag.
This fact will come more Into evidence in the future, as the art of soaring over flat country gains more adherents. One must of course be clear as to the limitations to the range of activity of any particular sailplane. At present the construction of machines which are equally suited to the lightest of winds and the heaviest of thunderstorms remains something of a problem.