C.Owers Hansa-Brandenburg Aircraft of WWI Vol.1: Landplanes (A Centennial Perspective on Great War Airplanes 17)

Type ZM and Austro-Hungarian Type GF

   The battleplane concept of the early war days evolved into the weight lifter and then the bomber as we now accept the designation. The ZM was a twin-engined battleplane originally built for the German Navy, and was the first twin-engined aircraft built by Brandenburg. The ailerons were mounted on the outer interplane struts of the three bay wings. The Austro-Hungarian Army ordered a prototype as the Type GF that was delivered as serial 05.05. Whether this was the same machine as that ordered by the German Navy is unknown, nor is any data available for its use, if any, by that service.
   Equipped with crude bomb racks, 05.05 was pressed into service and was lost in a landing accident returning from a raid on Chiopris on 6 April 1916. According to Heinkel data it could carry 50 x 5-kg bombs, and it is assumed, an equivalent of larger bombs if suitable carriers were available. It was equipped with two machine guns. The type never overcame the problem of not being able to fly on one engine and was reported as unsuitable for front-line service.

Brandenburg Type ZM Specifications
Source Typenschau Brandenburg 3-View
Span, m 17.50/26.73 27.500
Length, m 15.70 15.700
Wing Area, m2 144 144
Motor 160-hp Maybach 160-hp Maybach

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

Brandenburg 05.05

  Prior to the war, some military planners saw aerial combat in a naval context, fought by giant battleplanes heavily armed with cannon and machine guns. Indeed, every belligerent power built at least one such aircraft. On 25 May 1915, the LFT ordered a prototype battleplane from Hansa-Brandenburg, known as the Type GF and developed from the Type ZM bomber originally built for the German Navy. The prototype, designated 05.05 (work number GF 52) was powered by two 160 hp Mercedes tractor engines. The wooden fuselage was plywood covered and fitted with two gun positions fore and aft. Triple rudders provided limited maneuverability with one engine out.
  Upon joining the LFT (date unknown), the 05.05 was sent to the Isonzo Front for evaluation, but operational records are lacking. On 15 October 1915, an unpredictable bora storm severely damaged the airframe. Repair and installation of rudimentary bomb racks were completed by the Phonix factory on 6 March 1916. The Brandenburg 05.05, assigned to Flik 19 in March, was totally destroyed on 6 April 1916 in a landing accident after returning from a bombing raid. Perhaps it was this event that gave cause for Flars to report the bomber as unsuitable for frontline service owing to its inability to fly safely or remain aloft on one engine. Unfortunately, the engine-out problem was never satisfactorily solved by Brandenburg, much to the detriment of the improved G.I (type GF) bomber, series production of which was already underway.

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

01. — 010. Flugzeuge ausländischer Produktion (Самолеты иностранного производства)
05.05 Brandenburg Type ZM 2 x Merc 160