Flight, February 12, 1915.
THE EVOLUTION OF THE ETRICH "TAUBE."
The experiments of Santos Dumont prompted Etrich to try once more power-driven flights, this time on a larger scale, so a 24 h.p. Antoinette engine was obtained and installed in the glider as shown in (b) Fig. 2. It will be seen that the planes still followed very closely the Zanonia leaf, but in order to effect better directional control a small elevator was fitted in front close up to the leading edge, whilst it was also possible to flex the wing tips. The engine was mounted below the plane in the under-carriage frame, and drove by means of a chain a crude form of variable-pitch propeller located slightly below, and almost in the centre of the plane, a portion of the latter being cut away so as to clear the propeller. The pilot was seated in much the same position as on the glider, and controlled the elevator by means of the pedal, the wing tips and the pitch of the propeller blades being operated by hand wheels. The under-carriage consisted of two solidly-built skids, and a pair of running wheels, supporting the plane about 1 m. above it by bamboo struts. This machine had a span of about 10 m., and an overall length of 5.4 m., the chord at the centre being 4.25 m. Etrich had originally intended fitting a 50 h.p. engine, but Wels favoured one of smaller horse-power, and persuaded him to fit the 24 h.p. engine. The ultimate trials, however, proved that this was by no means a powerful enough engine, and once again they failed to obtain extended flights. It is true that one or two hops were made, but these, it must be owned, were due to sudden wind gusts. However, they continued experimenting along these lines, making various alterations in design. For instance, the second trials, in 1908, were made with a tractor machine (b) Fig. 2. The Zanonia-form plane remained much the same, and the 24 h.p. Antoinette engine was still employed, but the whole machine was considerably lighter. The engine was mounted forward under the plane, and drove a tractor screw direct, whilst the pilot sat behind the engine, also under the plane. The under-carriage consisted of a simple framework to which was sprung, by means of full elliptic springs, a pair of running wheels. Behind the latter were two skids which prevented the machine from tilting over backwards. Although in some respects a distinct improvement on the previous model, this machine also was a failure, and did not appear to possess the stability of the original glider, whilst the advisability of fitting an elevator was also demonstrated. It was not until the next year, 1909, that Etrich, working on his own account - Wels having left him - achieved any notable success, making short flights on the old Wels-Etrich machine. He had made several alterations to this machine, (c) Fig. 2, notably the fitting of a front elevator, a rear vertical rudder, and a propeller mounted immediately behind the trailing edge. He also subsequently fitted an Anzani engine in place of the Antoinette. The first flight on this old machine was made on July 20th, when a distance of nearly 100 m. was flown, after which several other "hops" were accomplished from time to time until it "disintegrated" in September the same year.