Flight, December 1932

FOR METEOROLOGICAL OBSERVATIONS
The Focke-Wulf A.47

   DESIGNED specifically for meteorological observations, the Focke-Wulf monoplane shown here is not a high-performance machine, but an endeavour has been made to make it very stable, so that when much cloud-flying has to be done, as must often be the case, the machine is easy to fly "blind." Good climb and a high ceiling were considered more important than speed, and in fact a high speed was regarded as a definite disadvantage, since it might, on occasion, lead to the machine getting too far away from its starting point during an altitude flight in the clouds.
   The construction of the A.47 is the usual Focke-Wulf, with a one-piece wing of all-wood construction, and a welded steel tube fuselage. The wing tips show the Zanonia form associated with all Focke-Wulf machines, and which has been found by this firm to give added lateral stability. The wing is carried on steel tube pyramids well above the fuselage.
   The engine fitted in the A.47 is the new Argus As. 10, an eight-cylinder Vee inverted air cooled, with direct airscrew drive. Later it is proposed to fit a supercharged engine of the same make.
   An unusually extensive equipment of instruments is carried, partly for making meteorological observations, and partly to enable the crew to fly "blind" for considerable periods.
   The main dimensions of the Focke-Wulf A.47 are as follows: Length o.a., 10.5 m. (34 ft. 6 in.); wing span, 17.76 m. (58 ft. 3 in.); wing area, 35 m.2 (377 sq. ft.). The tare weight is 950 kg. (2,090 lb.), and the disposable load 525 kg. (1,155 lb.), giving a gross weight of 1,476 kg. (3,245 lb.), a wing loading of 42,2 kg. /m.2 (8,62 lb./sq. ft.) and a power loading of 6.7 kg./h.p. (14.75 lb./h.p.).
   The maximum speed at ground level is 172 km./h. (107 m.p.h.), and the landing speed 77 km./h. (48 m.p.h.). The climb to 4,000 m. (13,100 ft.) takes 34 minutes. The best gliding angle is given as 1 in 10.8.