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

Saliger Three-Engine Bomber

  Before he went to Oeffag in early 1917, Ingenieurleutnant Karl Saliger was attached to the Flars construction section. In January 1917, Saliger submitted a proposal for a bomber powered by one 300 hp Daimler V-12 tractor engine and two 200 hp Hiero pusher engines. The empty weight was projected at 2630 kg, the loaded weight at 3470 kg, with a useful load of 390 kg. There appears little doubt that this design was the pattern for the Aviatik 30.23 bomber that was built under government supervision.


Aviatik 30.23

  Flars reported on 29 December 1916 that a new three-engined bomber project would shortly be submitted for approval. The layout and specifications were completed in January 1917 by Ingenieurleutnant Karl Saliger of the Flars bomber group. Powered by one 300 hp Daimler V-12 and two 200/230 hp Hiero pusher engines, the bomber was designed for a crew of three and a bomb load of 440 kg (882 lb). Construction of two prototypes, designated 30.23 and 30.34, was assigned to Aviatik under a cost-plus-fixed-fee contract under Flars supervision. Work on two prototype bombers began in February 1917 with completion scheduled for April-May 1917.
  Progress was slow. In January 1917, Saliger transferred to Oeffag leaving Aviatik engineers, who were already fully occupied with in-house projects, to set the pace. After Saliger's death in July 1917, Berg assumed engineering control, and probably this was the reason that the 30.23 became known as the "Berg" bomber. In June 1917, the 30.23 bomber's fuselage was complete and the flying surfaces were in the process of being covered.
  "Bureaucratic inertia", according to Berg, had delayed engine delivery but, in fact, other programs had been given priority. Consequently, it was not until 7 January 1918 that the 30.23 bomber was completed. Ground trials commenced on 6 March, followed by the maiden flight on 13 March, with satisfactory performance reported. Because the rudder response was felt to be inadequate, three configurations were tested before the correct shape was found. The single wheels were replaced by twin wheels. Finding the proper configuration airscrew to maximize performance proved, as always, extremely time-consuming. Berg wanted to employ reduction gearing to lower propeller revolutions, but Ingenieur Kolin calculated that the power loss would be excessive. Speed and climb trials, on 5 April, 27 April and 24 May 1918, demonstrated results that "compared favorably with contemporary German bombers." On that basis, Flars ordered four additional bombers on 29 May 1918 (see Aviatik G.III series 131).
  On 7 August 1918, contingent on completing a three-hour duration flight, the 30.23 prototype was scheduled to join Flik 102/G for evaluation. The 30.23 prototype was formally accepted by the LFT in October 1918 and remained at Aspern until the war's end.

Aviatik 30.23 Specifications
Engine: 300 hp Daimler & 2 x 230 hp Hiero
Wing: Span Upper 17.10 m (56.10 ft)
Total Wing Area 83.6 sq m (900 sq ft)
General: Length 12.30 m (40.35 ft)
Empty Weight 2681.6 kg (5913 lb)
Loaded Weight 3784.1 kg (8344 Ibj
Maximum Speed: 110 km/hr (68 mph)
Climb: 1000m (3,281 ft) in 5 min 29 sec
2000m (6,562 ft) in 13 min 10 sec
3700m (12,139 ft) in 45 min


Aviatik 30.34

  Aviatik began construction of two bomber prototypes, 30.23 and 30.34, in February 1917. The fuselage of 30.34 was ready for the plywood covering in June when work was halted to give priority to 30.23 completion. In December 1917, Aviatik proposed replacing the center engine by a forward gun turret, mounting the outer engines as tractors, and dividing the undercarriage to allow bomb rack installation under the fuselage. Calculations submitted by Aviatik showed that the bomber would have greater reliability due to reduced engine and fuel weight. Flars rejected the proposal but approved the installation of three 230 hp Hiero engines and urged that work start at once. The 30.34 was reported "almost complete" on 15 March 1918. In a letter dated 24 August 1918, Aviatik complained to Flars that the program had been neglected, nor had the Hiero engines been delivered - this at a time when the LFT command urged the development of the Aviatik G.III prototypes "by all possible means." Even so, at war's end the 30.34 was only 80 percent finished.


Aviatik G.III Series 131

  On 15 March 1918, two days after the maiden flight of the three-engined 30.23 prototype, Flars confirmed an order for four pre-production bombers, designated Aviatik G.III series 131, intended for weapons trials and service evaluation. The contract was signed on 29 May 1918. Loosely based on the 30.23 and 30.34 layout, the series 131 was designed around three 230 hp Hiero engines and fitted with a split undercarriage. On 23 July 1918, Berg submitted project specifications for three versions:
  Version 1: a day bomber carrying three crew members, armed with three machine guns and capable of lifting a 400 kg (882 lb) bomb load.
  Version 2: a night bomber with a two-man crew, armed with two machine guns and a bomb capacity of 1000 kg (2205 lb).
  Version 3: a ground-attack machine armed with three guns, carrying extra ammunition but no bombs, and 300 kg (662 lb) of armor plate to protect the three-man crew.
  To improve lift, Flars proposed a 50 percent wing-area increase over the 30.23. Uzelac suggested fitting the 30.23 with a nose turret to increase firepower and using the center engine to drive a supercharger to attain higher altitude. These suggestions were rejected, although in August 1918 Flars approved plans to fit two G.III bombers with a nose turret in place of the third engine. Details of the final design are unknown, but the configuration of the production bomber was contingent on the flight test results of the two prototypes at the time under development. Flars urged work on the G.III to proceed "with all possible speed" and placed a production order for an additional 25 bombers. Provided the operational trials were successful, the production would be increased to 50 machines at the expense of Fokker D.VII(Av) output. As projected in August 1918, Aviatik was slated to deliver the first of 29 G.III bombers in October 1918 and continue at the rate of three bombers per month through August 1919. As reported on 31 October 1918 when assembly work was halted, two G.III airframes were 20 percent and two 15 percent complete.
  The Aviatik G.I and G.II have not been identified in LFT records. It is believed that these designations may have been reserved for the 30.23 and 30.34 prototype bombers after being removed from prototype status arid sent to the Front for evaluation.

Aviatik G.III Series 131 Day Bomber Specifications
Engine: 3 x 230 hp Hiero
Wing: Total Wing Area 126 sqm (1356 sq ft)
General: Empty Weight 2500 kg (5513 lb)
Loaded Weight est. 3865 kg (8522 lb) est.

Aviatik G.III Series 131 Night Bomber Specifications
Engine: 3 x 230 hp Hiero
Wing: Total Wing Area 126 sq m (1356 sq ft)
General: Empty Weight 2500 kg (5513 lb) est.
Loaded Weight 4425 kg (9757 lb) est.

Aviatik G.III Series 131 Ground Attack Specifications
Engine: 3 x 230 hp Hiero
Wing: Total Wing Area 126 sq m (1356 sq ft)
General: Empty Weight 2500 kg (5513 lb| est.
Loaded Weight 3610 kg (7960 lb) est.

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

30. Flugzeuge der Österreichischen Aviatik-Werke Wien, Stadlau
30.23 Berg G Prototyp für G.I 2 x H 230, 1 x Dm 345
30.34 Berg G Prototyp für G.I 2 x Dm 200, 1 x Dm 300
131.01 Aviatik G.I Berg (Projekt)