Flight, September 18, 1914.
AIRCRAFT "MADE IN GERMANY"
WHICH MAY BE EMPLOYED AGAINST THE ALLIES.
30. The New Rumpler Taube
is of an improved type, chiefly as regards the wing bracing, which in this machine is effected by means of stranded cables instead of the girder structure under the wings. The bracing cables are taken to pyramidal cabanes or pylons above and below the fuselage, and instead of the flexing wing tips usually found on monoplanes of the Taube type, upturned ailerons are fitted. These, it should be noted, are hinged along an axis forming an angle with the transverse axis of the main planes. The only feature constituting this machine one of the Taube class is its Zanonia-form wings, it otherwise following standard practice as regards its fuselage, tail planes and chassis. The flexing elevator has been replaced by one of the hinged, divided type, whilst the rudder is hinged to the stern post, and not half above and half below the fuselage. The chassis is built up of four steel tubes forming two pairs of Vs, in the angle of which rests the axle, which is sprung by rubber shock-absorbers. Evidently the reduction of head resistance effected by substituting cable bracing for the girder structure under the wings has considerably increased the speed, for with a 100 h.p. Mercedes engine this machine is capable of doing about 74 m.p.h.
Flight, July 9, 1915.
THE RUMPLER-TAUBE MONOPLANE.
ALTHOUGH at the present time the Germans are not using the Taube type of monoplane so much as at the commencement of hostilities, they have not entirely abandoned them, and in fact efforts are being made to bring them more into line with other types of monoplane as regards speed. This is especially noticeable in the case of the Rumpler-Taube, which is described in the following notes.
Viewed from this standpoint, the prominent features of the Rumpler-Taube will be seen to consist in the absence of the girder understructure bracing the wings - a distinctive characteristic of nearly all Taubes - the hinged balancing flaps, and the orthodox type of tail planes in place of the original flexing plane. Though somewhat modified, the main planes still have the Zanonia form, and in addition they are very slightly swept back. The angle of incidence decreases towards the tips, where the balancing flaps present a slight negative angle of incidence. An interesting point in connection with these balancing flaps, which have an area of 15 sq. ft. each, is that they are hinged along an axis forming an angle with the transverse axis of the main planes. They also operate in an upward direction only, so that a downward reaction is presented on the side of the higher wing. Cable bracing is employed top and bottom, the cables in each case being anchored to pyramids of tubular steel struts mounted above and below the body respectively; the underbracing is thus quite independent of the undercarriage, and should the latter become strained the adjustment of the planes is not disturbed. Ash and American white pine are employed in the construction of the main planes, which are built up on two main spars situated fairly close together. Portions of the planes adjacent to the pilot's cockpit are cut away in order to provide a view below. The tail consists of a triangular stabilizing surface, in two portions mounted one on either side of the body, and two elevator flaps hinged similarly to the balancing flaps, i.e., at an angle. The vertical rudder is mounted between the elevators with a triangular vertical fin in front.
The body is rectangular in section, tapering to a vertical knife-edge at the rear. Ash is the material employed in its construction, and the portion forward of the cockpits is covered with sheet metal, and that aft with fabric. The engine, a 100 h,p. 6-cylinder water cooled Mercedes, is mounted in the nose, with the Windhoff radiator directly above it. This radiator is made up of aluminium tubes, and being mounted immediately above the engine, the water in the jackets is always under pressure, thus preventing air locks or vapour pockets. The engine drives direct a Reschke tractor screw 8 ft. 6 ins. diameter and 4 ft. 9 ins. pitch. Immediately behind the engine are the fuel tanks, and then come the pilot's and passenger's cockpits, the pilot being seated behind the passenger. The control consists of a vertical wheel mounted on a rocking column, the former operating the balancing flaps and the latter the elevator, whilst the rudder is actuated by pedals. A simple but strong under carriage is fitted consisting of two pairs of steel V struts of streamline section, with a tubular axle carrying a pair of disc wheels, attached, by means of rubber bands, to the apex of each V. A short skid attached to the body at the rear protects the tail.
The following are the main characteristics of the Rumpler-Taube :- Span, 46 ft.; maximum chord, 9 ft. 6 ins.; overall length, 27 ft.; supporting area, 300 sq. ft.; weight fully loaded, 1,840 lbs.; speed, 74 m.p.h.; climbing speed, 2,600 ft. in 6 mins. (full load, 4 hours fuel and 400 lbs. useful load).