O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Halberstadt D IV
   Penultimate aircraft in the Halberstadt lighter lineage was this D IV of 1917. The neatly spinnered nose and the ply-skinned fuselage shape were characteristics later to be seen in the firm's CL II. The large, balanced ailerons were operated through torque tubes in the upper wing actuated by long external push rods at the centre-section. The neat cowling of the motor is worthy of attention. Engine, 150 h.p. Benz Bz III. Span, 8.8 m. (28 ft. 10 1/2 in.). Length, 7.3 m. (23 ft. 11 1/2 in.). Height, 2.75 m. (9 ft. 0 3/8 in.). Area, 24 sq.m. (259 sq.ft.). Weights: Empty, 525 kg. (1,155 lb.). Loaded, 737 kg. (1,621 lb.). Duration, 1 1/2 hr. Armament, one or two Spandau machine-guns.

W.Green, G.Swanborough The Complete Book of Fighters

HALBERSTADT D IV

   On 9 March 1916, the Halberstadter Flugzeugwerke was awarded a contract to develop a twin-gun fighter powered by a 150-160 hp engine. Designated D IV and powered by a 150 hp Benz Bz III engine, the new fighter was an elegant single-bay biplane with a neatly-cowled power plant. Three prototypes were ordered, of which one was for static load testing. Submitted at Adlershof in October 1916, the D IV was rejected by the Idflieg because of "unsatisfactory cabane design", but served as a basis for the highly successful Cl II two-seat fighter.

Loaded weight, 1,819 lb (825 kg).
Span, 27 ft 63/4 in (8,40 m).
Wing area, 258.34 sq ft (24,00 m2).

J.Herris Halberstadt Aircraft of WWI. Volume 2: CL.IV-CLS.I & Fighters (A Centennial Perspective on Great War Airplanes 45)

Halberstadt D.IV

  The Halberstadt D.IV was more powerful than the other Halberstadt fighters, being fitted with a 150 hp Benz Bz.III engine. At the request of frontline pilots, it was fitted with two machine guns for increased fire power.
  As was typical for Idflieg, three prototypes were ordered; one for flight testing, one for static load testing, and one spare. The order was awarded on March 8, 1916 which is before the Halberstadt fighters arrived at the front.
  The D.IV arrived at Adlershof for testing in October 1916. Elegant and well-streamlined, the D.IV also had only a single bay of bracing for reduced drag.
  Rejected by Idflieg for the 'unfortunate choice of cabane design' no further information was given. However, inspection of the photos shown here may reveal the problem. It is easy to see that the explanation of the "unfortunate choice of cabane design" likely referred to the aileron push-pull rod design for the operation of the aileron control horns. This feature was not used by later Halberstadt designs. Idflieg reported that 'the D.IV will be demonstrated again after modifications have been made' but no results are known.
  Although not selected for production, the D.IV was developed into the very successful Halberstadt CL.II.
  It is not known why the D.IV was not successful in being chosen for production. The D.II and D.III were successful fighters that were well-liked by their pilots. They were more robust and maneuverable than the competing Albatros D.III fighters and, unlike the somewhat fragile Albatros D.III, never suffered a reported structural failure.
  With a modified cabane, the D.IV would seem to be natural for production, especially given the ease with which it was developed into the very successful CL.II. Was the powerful Albatros company involved in the decision to not produce the Halberstadt D.IV fighter but instead develop it into the CL.II? Through close personal relationships that likely involved corruption, Albatros had a special influence on the Prussian authorities who procured aircraft. Did they establish a somewhat corrupt monopoly on fighter orders in late 1916/early 1917, with the relatively small Halberstadt company given a consolation prize with orders for a new, unproven category of aircraft? Or did the Albatros fighters win their predominance in fighter production purely through their obvious merit? At this remove, we will never know the answer to these interesting questions.


Halberstadt Fighter Type Description
Type Engine Ailerons Wings Remarks
D.IV 150 hp Benz Bz.III Inset triangular balanced ailerons. Aileron push-pull rod controls Prototypes only. Twin machine guns


Halberstadt Fighter Specifications
Spec \ Type D.l D.II D.III D.IV D.V
Engine 100 hp Mercedes D.l 120 hp Mercedes D.II 120 hp Argus As.II 150 hp Benz Bz.III 120 hp Argus As.II
Span, upper - 8.8 m 8.8 m 8.4 m 8.8 m
Span, lower - 7.92 m - - 7.8 m
Chord, upper - 1.52 m 1.52 m 1.5 m 1.5 m
Chord, lower - 1.52 m 1.52 m - 1.5 m
Wing Area 24.0 m2 23.6 m2 23.6 m2 24.0 m2 23.6 m2
Length - 7.3 m 7.3 m - 7.3 m
Weight empty 551 kg 520 kg 525 kg - 600 kg
Weight loaded 739 kg 730 kg - 815 kg 812 kg
Speed - - - - 160 km/h
Climb
1,000 minutes 4.5 3.5 4 - 4
2,000 minutes 10 8.5 9 - 9
3,000 minutes 18.5 14.5 15 - 15
4,000 minutes 35 22.5 - - 24
5,000 minutes - 38.5 - - -
D.II(Av) Empty Wt. 575 kg, Loaded Wt. 728 kg.
D.II(Han) Empty Wt. 561 kg, Loaded Wt. 744 kg


Halberstadt Fighter Production
Order Date Quantity Type Engine Serial Numbers & Notes
March 8, 1916 3 D.IV 150 hp Benz Bz.III (*) Unknown
(*)Other sources give the engine as a 160 hp Mercedes D.III.