Messerschmitt M.24

M.24 был самым маленьким в семействе самолетов M.20. Машина, рассчитанная на перевозку 8 пассажиров, была построена в 1929 году. На первом из двух прототипов стоял мотор Junkers Jumo мощностью 280 л.с., на втором - BMW Va в 320 л. с. Биографы Вилли Мессершмитта говорят еще о двух построенных M.24b с моторами Pratt & Whitney Hornet (собраны по лицензии на заводе "BMW"). Один из этих самолетов был оснащен поплавковым шасси.

Flight, October 1928

Berlin Aero Show 1928

The B.F.W. M.20

   The Bayerische Flugzeug Werke, of Augsburg, is the firm which took over the Udet Co. some years ago, and of which Herr Hermann was then chief designer. The new firm has chosen as their chief designer Herr Willy Messerschmitt, who will be familiar to readers of FLIGHT as the designer of the little Messerschmitt monoplane with Bristol "Cherub" engine on which some very noteworthy flights were made a few years ago. At the I.L.A. Herr Messerschmitt is represented, on the B.F.W. stand, by a series of different types, of which the large commercial monoplane M.20 forms the subject of the present notes.
   Built entirely of metal, the M.20 is a pure cantilever monoplane of large dimensions and considerable load-carrying capacity. The extremely comfortable cabin has seats for 10 passengers, and, as in the case of the Albatros L.73, the seats are arranged to be capable of being tilted back to form couches should the passengers desire to sleep.
   A large sloping wind-screen in front of the pilots' cockpit, itself placed ahead of the wing, affords ample protection against the weather, and, at the same time, the opening left in each side enables the pilot to lean out should the windows be covered with moisture or snow, or in taking off or alighting. The fuselage construction is entirely of metal, mostly Duralumin, and the covering is in the form of flat sheet, stiffened by widely-spaced longitudinal corrugations.
   The wing construction is of considerable interest, since Herr Messerschmitt has incorporated in it his experience with very small monoplanes. Readers of FLIGHT who studied German glider design before the subject lost interest in England will possibly remember that a form of wing construction became very popular in Germany by which but a single spar was employed, this forming, in conjunction with a three-ply nose covering, a sort of box of D-section, which was found very strong not only in direct bending but also in torsion. This same principle has been applied by Herr Messerschmitt in the case of the M.20, only metal has been substituted for the three-ply wood. The single main spar is of double T section, and placed at the deepest point in the aerofoil. A fairly substantial metal covering over the leading edge and extending some distance aft of the spar serves to form, with the spar, the D-section box of the earlier small machines. We are informed that sand load, etc., tests have proved the wing to have a very excellent strength/weight ratio, and the structure weight of the machine would seem to indicate very economical construction. One criticism of the wing comes to mind in connection with the one-piece construction. A monoplane wing of such dimensions must be rather difficult to transport. The two petrol tanks are housed inside the wing, one on each side of the fuselage. Their total capacity is 716 litres (157 gallons).
   The main dimensions and weights of the B.F.W. M20 are: Length o.a., 14-9m. (48-8 ft.); wing span, 25-5m. (83-6 ft.); wing area, 65 sq. m. (700 sq. ft.). Weight empty, 2,400 kg. (5,280 lbs.). Permissible load, 2,100 kg. (4,620 lbs.). Total loaded weight, 4,500 kg. (9,900 lbs). Engine B.M.W. VI, with compression ratio, 5-3:1. Farman reduction gear. Maximum power, 700 b.h.p. at 1,700 r.p.m.; normal power, 500 b.h.p. at normal speed of 1,530 r.p.m. Wing loading, 69 kg./sq. m. (14 15 lb./sq. ft.). Power loading (on normal power), 19-8 lb./b.h.p. Maximum speed at ground level and normal power, 175 km./h. (108-5 m.p.h.); cruising speed near ground at 10 per cent, throttling, 154 km./h. (95-6 m.p.h.). Climb to 1,000 m. (3,280 ft.) in 8 minutes. To 2,000 m. (6,500 ft.) in 17 minutes. To 3,000 m. (9,840 ft.) in 27 minutes. Ceiling, 5,000 m. (16,400 ft.). Normal range 880 km. (550 miles).