J.Herris DFW Aircraft of WWI (A Centennial Perspective on Great War Airplanes 29)

DFW Mars Two-Seaters

   The Mars monoplane was designed and built in 1912, the same year as the Mars-Buchner biplane was built. The standard Mars biplane was developed from the Mars-Buchner biplane with a more robust wing cellule. The Mars monoplane and biplane were similar in appearance other than their wings.
   The Mars monoplane originally had a four cylinder engine but most had a six-cylinder, 100 hp Argus, Daimler, or NAG engine. The wings were designed to fold. Most used wing warping for roll control although at least one had a modified wing that featured ailerons.
   The Mars biplane also originally used four-cylinder engines like the 95 hp NAG, Daimler G4F, and others. Once more powerful six-cylinder engines became available the later production Mars biplanes used these more powerful engines. The wing cellule was a robust, three-and-a-half bay design that was also designed to fold the wingtips for storage in tents while in the field.
   Both the Mars monoplane and biplane were two-seat aircraft that could be used for reconnaissance and training. In 1913 a Mars biplane was flown for the Turkish side in the was against Bulgaria, and a long reconnaissance flight was flown with Captain Kemal Bey, later to become president of Turkey Kemal Attaturk.
   Small numbers of the Mars biplane were flown at the front during the early part of the Great War, and it is possible that Mars monoplanes were also used at the front. Certainly both types were used for training before and after the beginning of the war.

DFW Mars Specifications
Monoplane Biplane
Engine 100 hp NAG 100 hp Mercedes D.I
Span, Upper 16.8 m 17.0 m
Wing Area 35 m2 46 m2
Length 9.7 m 9 m
Height - 3.18 m
Empty Weight 560 kg 700 kg
Loaded Weight 820 kg 920 kg
Maximum Speed 120 km/h 100 km/h

Jane's All The World Aircraft 1913

MARS. Deutsche Flogzeugwerke G.m.b.H., Lindenthal bei Leipzig. Established 1911. This is one of the most important and successful aviation works in Germany. Capacity: from 80 to 100 machines a year.

   1911-12. 1912. 1912
   Monoplane. Biplane. Hydro-
   aeroplane.

Length...........feet(m.) 31 (9.7) 31 (9.7)
Span.............feet(m.) 55? (16.8) 57 (17.8)
Are.........sq. feet(m?.) 376 (35) 495 (46)
Weight, total, lbs.(kgs.) 1234 (560) 1434 (650)
   useful, lbs.(kgs.) 1808 (820) 2006 (910) Building
Motor................h.p. 95 N.A.G. 95 Mercedes
Speed, max....m.p.h.(km.) 120 (75) 115 (71)
   min....m.p.h.(km.) ... ...
Endurance............hrs. 5--6 4--6
Number Built during 1912 6 16


Remarks--

P.Grosz, G.Haddow, P.Shiemer Austro-Hungarian Army Aircraft of World War One (Flying Machines)

DFW Mars Monoplane 00.01

  Heinrich Bier, technical director of the Deutsche Flugzeug Werke (DFW) in Leipzig and designer of the DFW Mars aircraft, demonstrated a Mars monoplane at Aspern on 11 January 1913 for the benefit of the military authorities who were so impressed that one Mars monoplane (w/n 24, less engine) was purchased for study purposes. The LA installed a 85 hp Hiero engine and promptly discovered that the Mars could not be tested at Mostar or Gorz because the hangars or tents were too small to accomodate the large wingspan; consequently it remained at Fischamend. Assigned serial number 00.01 in February 1915, the Mars monoplane was written-off in August or October 1915.

E.Hauke, W.Schroeder, B.Totschinger Die Flugzeuge der k.u.k. Luftfahrtruppe und Seeflieger 1914-1918

00. Versuchs- und Beuteflugzeuge
00.01 D.F.W. Mars, WNr. 24 Merc 100

Журнал Flight

Flight, July 13, 1912.

THE MILITARY COMPETITION - THE MACHINES.

THE MARS MONOPLANE.

   FLYING under the official number 23 in the Military Aeroplane Trials will be a machine called the Mars, entered by Mr. C. E. Kny, and constructed in the Deutsche Flugzeug Werke at Leipzig.
   As the photograph shows, this monoplane is of interesting and original design. It has a completely covered body, in which two cockpits are provided for the pilot and passenger; the latter, who in a military aeroplane would be the observer, has a position in front of the pilot, and a clear outlook over the wings. Both pilot and passenger have the appearance of being seated very high in the machine, and, similarly, the wings seem to be low-pitched; but in reality this is mainly due to the protective covering that arches over the top of the boat-shaped body.
   The engine, a 100-h.p. Mercedes, is situated in the extreme front, and short exhaust pipes discharge the gases below the level of the wings. The wings themselves are built somewhat on the lines of the Etrich, at least, they have the characteristic Etrich upturned tips. The elevator and rudder are situated in the tail, which, by the way, is braced by long diagonal wires to the triangular mast above the cockpit. Corresponding wires pass downwards beneath the body to the main struts of the undercarriage, which is especially worthy of close examination as an interesting feature of construction. In all probability, Lieut. Bier, who is at the wheel in our photograph, will fly this machine; it has already attained a speed of 80 m.p.h. when fully loaded with passenger and fuel for four hours. The weight of the machine is about 1,170 lbs. The span is 53 ft. and overall length just under 45 ft.; the supporting surface is 350 sq. ft.


Flight, November 8, 1913.

THE D.F.W. MILITARY MONOPLANE.

   BEFORE beginning a description of the machine itself, a few words about the German Aircraft Works (Deutsche Flugzeug Werke) in which these machines are built may not be amiss. One of the accompanying photographs gives a good idea of the spacious shops of this firm, whose works are situated at Lindenthal, near Leipzig, Germany. The shops are equipped with the most up-to-date machinery, and in the three erecting shops as many as 20 machines can be assembled at a time. The number of employees, we understand, has passed 300, and is constantly on the increase. At the present time four standard types of machines are turned out, i.e., a school monoplane, a military monoplane, a military biplane and a hydro-biplane. All of these types are designed with a view to obtaining a certain amount of inherent natural stability as will be explained later. Another point which has received careful attention is the standardization of all parts, most fittings on both monoplanes and biplanes being interchangeable.
   Our scale drawings and photographs this week illustrate the military type monoplane, which the school monoplane resembles in every respect, with the exception of the steel bridge girder fitted underneath the wings of the latter. The fuselage is built up of a framework of steel tubes of ample dimensions, laterally stayed by three ply wood panels. The section of the fuselage is a very elongated ellipse, having its major axis vertical. Inside the fuselage are the pilot's and passenger's seats, arranged tandem fashion, the passenger occupying the front seat, from whence he has an excellent view of the ground beneath, and, if necessary, can make any little adjustments of the engine that may be required. The pilot's seat is placed sufficiently far behind the trailing edge of the main planes to give him an unrestricted view in a downward direction, and so enable him to judge his landings with a great amount of accuracy.
   Only engines of the stationary type are fitted, as the constructors of the machine contend that, although somewhat heavier than rotary engines, the stationary engine is more reliable and economical in fuel consumption, two most important qualities in a machine for military use.
   The dome-shaped honeycomb radiator is mounted directly in front of the engine which position, in addition to being the best possible for cooling purposes, gives a good streamline form to the fuselage. The bonnet over the engine consists of fine wire gauze, making all engine parts visible, preventing overheating and affording accessibility, as the bonnet opens in sections. The petrol and oil tanks are situated between the passenger's and pilot's seats, and a smaller service tank is mounted on top of the fuselage.
   An inspection of the plan view will show that the main planes possess that feature which seems to characterise the majority of German machines, i.e., the back swept wing tips, set at a small negative angle of incidence. In this machine the outer extremities of the wings take the shape of ailerons, being hinged to the rear spar instead of being formed by extending the outer ribs backwards, which is the usual method of construction. The method of having the extensions hinged in this way has proved very satisfactory.
   The tail planes consist of a stabilizing plane, which is not, however, rigidly connected to the fuselage, but is pivoted, and may be adjusted from the pilot's seat by means of a rotatable hand wheel situated outside the fuselage, and within easy reach of the pilot's seat. Hinged to the trailing edge of this plane is the undivided elevator. On top of the fuselage is the rudder, which is hinged to the trailing edge of a small vertical fin. A well-sprung tail skid protects the tail planes from contact with the ground.
   In front of the pilot are the usual set of control levers, consisting of a rotatable hand wheel mounted on a central tubular column, which, in turn, is mounted on a transverse rocking shaft. A to-and-fro movement of the column operates the elevator, whilst rotation of the wheel actuates the ailerons. The rudder is operated by means of a footbar. Ignition and throttle levers are mounted on the right hand side of the pilot's seat, and on the hand wheel is a switch, while a self-starter is fitted on the instrument board in front of the pilot.
   The chassis consists of two "U"-shaped steel tube frames, braced by tubes from a point underneath the fuselage, the whole forming a very strong structure which offers comparatively little head resistance. Two pairs of wheels sprung in the usual way by means of rubber shock absorbers are mounted on the U-shaped frames, and facilitate starting from and alighting on the ground. If desired brakes can be fitted.
   Below we give a few particulars which, in connection with the scale drawings, should give a very good idea of the main characteristics of these machines which have met with a good deal of success in competitions, while a number of them have been purchased by the German military authorities :-
   Weight, empty: 1,300 lbs.
   Useful load: 440 lbs. and fuel for a 4 hours' flight.
   Average speed loaded as above: 73 m.p.h.
   Climbing speed: 3,300 ft. in 15 mins.
   Gliding angle : 1 in 7.5.