Zeppelin-Staaken. Семейство R
В послевоенное время построили еще один самолет-гигант - E.4/20, разработанный инженером Адольфом Рорбахом, радикально отличавшийся от своих предшественников. Это был транспортный высокоплан с четырьмя 245-сильными (183 кВт) ПД Maybach. Экипаж из двух человек размещался в открытой кабине, а в фюзеляже была организована кабина для 18 пассажиров. Прошедший испытания осенью 1920 года, самолет попал под ограничения Контрольной комиссии Союзников и был пущен на слом два года спустя.
Flight, March 1921
THE ZEPPELIN-STAAKEN ALL-METAL MONOPLANE
And a New Smaller Edition
WE have already published several photographs of the Zeppelin-Staaken monoplane, and a brief description of the machine, which is built of metal throughout, even to the wing covering, the metal chiefly used being aluminium alloy. On its test flights this machine is said to have given very good results, so much so that it rather surprised its designer, Herr A. K. Rohrbach. We understand that a cruising speed of about 120 m.p.h. is attained, and that the full speed is somewhere in the neighbourhood of 135 m.p.h. The wing area is approximately 1,150 sq. ft., and the weight fully loaded about 18,650 lbs. This gives a wing loading of 16.2 lbs./sq. ft., which is extraordinarily high even considering that the wing is of high-lift section. We have no figures of the landing speed, but it must be rather high for a commercial machine. The power loading is about 18 lbs./h.p., so that if the figures given for maximum speed are correct, the machine appears to be extraordinarily efficient as regards resistance. So much so that one very much doubts whether such a speed has ever been attained by the machine, except in a steep dive. It is true that the heavy wing loading would tend to increase the average figure, which is based on a wing loading of 7 lbs./sq. ft., but even so it is doubtful whether the speed is possible for that power loading.
Our correspondent does not inform us of any tests having been made with cutting-out one of the outer engines, but the fact that the distance from these to the centre line is so great would almost certainly result in a turning moment of such magnitude that the corresponding engine on the other side would have to be cut out, or at any rate throttled down. Thus in practice the cutting-out of one engine would really mean the loss of practically half the power.
The results attained with this first machine have been so promising that a second one, of slightly different type, is now being constructed. This machine, of which no photographs are available yet, will have two engines only, as shown in the photograph of the wind-channel model of the machine published herewith. This arrangement should be much better, as the two engines, by being pushed far forward and kept as close together as the airscrews will permit, are not far from the centre line of the machine. The object of placing the engines so far forward is evidently to help bring the nose of the fuselage back so as to avoid the gap between the two propellers that would otherwise be necessary if the body projected forward between them. What the effect on the front-wing spars will be is another matter. One would imagine that the down load in a dive, aggravated by the projecting engines, might prove somewhat heavy for the front-wing spars, especially as there is no top bracing. However, the wing is so deep in section that possibly the spar is capable of taking the stresses and allow of a reasonable factor of safety. Otherwise we think that the new monoplane is a great improvement on the older type. The cabin is low over the ground, and the door, when the tail is down, may be entered without the use of steps.
We do not know if the Inter-Allied Commission has passed this design, but for the sake of aviation in general it is to be hoped that the firm will be allowed to finish and test it, as it appears to incorporate ideas well worth trying out.
Глядя на совершенные формы E.4/20, даже не верится, что этот самолет был построен вскоре после окончания Первой Мировой войны. Будучи поистине "гостем из будущего", он, по понятным причинам, не вписался в реалии. А жаль...
Стойки, идущие от шасси, крепятся на амортизаторах и не разгружают крыло в полете. Поэтому схема самолета - не подкосный моноплан, как кажется на первый взгляд, а свободнонесущий высокоплан
The large aircraft was no longer a rarity by the end of World War I, thanks largely to the pioneering work of Sikorsky, Caproni, Handley Page and Farman. In this context, the often overlooked, short-lived Zeppelin Staaken E.4250. designed under the leadership of Adolf Rohrbach, deserves more than a fleeting mention. Starting life in 1918 as one of the new breed of German monoplane bombers, the four engined E.4250 was rapidly transformed into an airliner in the wake of the Armistice. Reported to have been briefly test flown towards the end of 1919, there were some indications that the machine was overweight for its total installed power. That may well have been the case, after all, such shortfalls were not that uncommon then, or, for that matter, for many years to come. What must be recognised is the visionary design approach of Rohrbach, who, taking the best of Hugo Junkers' and Claudius Dornier's innovations, came up with this magnificent design signpost to the classic high wing, monoplane airliner formula that was to be adopted by Fokker in Holland and by such Americans as 'Bill' Stout for his AT series and 'Jack' Northrop, for his Lockheed Vega design of 1928. Rohrbach's adoption of all-metal construction took longer to become universally accepted, with others following by the mid-1920s in the US; but it took about a decade longer in the case of all but a few of the more far-sighted European manufacturers.
THE ZEPPELIN-STAAKEN MONOPLANE: Three-quarter front view.
THE STAAKEN MONOPLANE: This machine, which is fitted with four Maybach engines of 260 h.p. each, was briefly described in our issue of October 28. Note the floral decorations
THE "ZEPPELIN STAAKEN": This machine was designed by Dr. Rohrbach and built in 1919. It was destroyed by order of the Inter-Allied Aeronautical Commission.
Adolf Rohrbach's very advanced E.4/20 which was built by Zeppelin-Werke at Staaken.
THE ZEPPELIN-STAAKEN MONOPLANE: Three-quarter rear view.
The Zeppelin Staaken Monoplane in Flight: This machine, which is built of metal throughout, was described in a recent issue of FLIGHT. It carries 18 passengers in a comfortable cabin. Our photograph gives an excellent idea of the arrangement of the engines. The yawing moment set up by the cutting out of one of the outer engines must be very great, and this feature would appear to be a very bad one in an otherwise good design.
The Zeppelin-Staaken Monoplane: View of the engine nacelle with cowling and radiator removed. In this photograph may be seen the very deep front wing spar, and the opening through which the mechanic crawls into the engine housing.
The Zeppelin-Staaken Monoplane: View of the engine nacelle from behind.
A new Zeppelin-Staaken Monoplane: Our photograph, the first to be published in this country, shows the wind channel model of this new machine which is now being built at the Zeppelin works. This machine, it will be seen, will have two engines only, placed comparatively close together, so that the turning moment when one engine stops should be quite small.