The Halberstadt biplane, was used in large numbers by the Germans during 1916, but, as it was almost invariably downed by French and British flyers, it apparently has since been abandoned. A brief review of its salient points shows that it would tend to be unstable to a degree unknown in any of the existing French or British types, which may account for the frequent occasions on which it has been known to end the career of its pilot by a spiral dive.
Top Speed: 90 m.p.h.
Engine: 120 h.p. Mercedes D II six-cylinder inline
Wingspan: 28 feet 6 inches
Weight: 1,696 lb.
Armament: 1 machine gun
Specifications from “Practical Aviation,” by Charles Hayward, 1919
Planes
In addition to being very poorly balanced longitudinally, the design of the machine throughout is crude and heavy. It is a single-seat type of short span, the upper wing measuring but 28 feet 6 inches and the lower, 25 feet 9 inches, but, despite this, it is built with two pairs of interplane struts and the usual wire bracing in the panels. This simply increases the drift unnecessarily without any compensating advantages, as practically all were built with a single pair of interplane struts on either side of the fuselage.
The chord is approximately 5 feet, and the gap is only 4 feet 3 inches, which brings the upper- wing very close to the body and to some extent reduces the efficiency of the lower wing. The wings have a slight dihedral and are staggered but have no sweep back.
Tail Unit
While a large balanced rudder is employed, there an entire absence of fixed vertical surface at this point and this condition is aggravated by the design of the fuselage, which. a horizontal knife edge, further reducing the balancing surface back of the center of gravity of the machine. The elevators are mounted on a spar attached to the rear end of the fuselage and the flat upper surface of the latter is depended on to act as a horizontal stabilizer, no other fixed surface being provided for this purpose. The vertical surface presented by the body just back of the wings is considerably increased by a high camber running from the rear of the pilot’s seat half the length of the fuselage—a feature of design that calls for an additional amount of vertical balancing surface at the tail instead of its reduction considerably below the normal, as is actually the case.
Power Plant
The engine is an Argus six-cylinder vertical water-cooled type rated at 120 h.p. Instead of the usual overhead camshaft, however, it is fitted with the ordinary type of rocker arm valve mechanism operated through push rods from camshafts at the level of the crankcase. The fuel tank has a capacity of approximately 17 gallons and serves as a seat for the pilot. From this tank the gasoline is elevated by a pump driven by the motor to a 4-gallon gravity tank built into the center section of the upper plane. The radiator, which is built to conform to the curve of the wing, is also located at this point and likewise a small water tank.
Either a leak or a puncture due to a machine-gun bullet would bring the hot water down directly on the pilot.