M.Schmeelke Zeppelin-Lindau Aircraft of WW1 (A Centennial Perspective on Great War Airplanes 42)

Zeppelin-Lindau CL.II
  
  Work on the CL.II was delayed until the summer of 1918. The new flying boat, the Rs.IV, the single-seat D.I fighter, and the Zeppelin (Ja) C.II had priority. The most noticeable improvement on the ZWL CL.II was the front radiator for the Daimler D IIIa engine. The wingspan of the upper wings was widened by 10 centimeters in order to improve the aircraft's climbing performance. In addition, the entire empennage was once again reengineered. The pilot was provided with an additional MG. On August 17th, 1918, Vzfw. Ruppert took the CL.II on its maiden flight in Zech. He reached a top speed of 164 kilometers/hour. The climbing performance had improved dramatically over the Cl.I. In order to make it even better, over the following weeks, the engineers tested different propellers. During a test flight on August 21st, 1918, Ruppert reached a maximum altitude of 5,200 meters with an Axial propeller with a length of 2.76 meters. The propellers from the companies of Wolf, Bechstien, and Heine were less effective and the LZ propeller proved to be completely unsatisfactory. On August 21st, one even broke during a flight.
  It is likely that just two CL.II aircraft were completed prior to the end of the war in November 1918. The photographs that survived show the aircraft's wings in various states of completion. Some had the 5-color printed camouflage fabric, others hand the 3-color hexagonal camouflage fabric of the navy. The location of the CL.II aircraft after the end of the war is unknown.
  It is unclear why IdFlieg did not strongly support introducing Dornier's Cl aircraft. Apart from its overall excellent speed and climbing performance results, they were also weatherproof by virtue of the fact they were built of metal. The traditional aircraft of the era, made of wood and fabric, such as the Rumpler C.IV or LVG C.V, were significantly more susceptible to weather. The air wings had to move their bases frequently during the offensives and retreat battles of 1918, and therefore it was often impossible to find hangars or tents to store the aircraft. In addition, airfield conditions - which often included levelled farmers' fields or marshy meadows - were sometimes catastrophic.
  Of course, the weather-resistant duraluminum also aged. A coat of paint acted as corrosion protection and prevented poor adhesion following the natural oxide rust and patina finish on the materials. Nevertheless, duraluminum was much more hardy and robust compared to traditional materials used for aircraft construction. This was obvious for example on the Zeppelin C.II aircraft, whose structure was made of duraluminum. These were used by the Swiss Air Force from 1919 until 1927. Only after about eight years did the first signs of material fatigue appear.
  There was rarely a problem with the repair of the metal aircraft because there was enough metalworking expertise in every airwing department. The airfields were also equipped with full maintenance facilities. A hugely important and vital piece of equipment for the pilots and the observers of the ZWL C-aircraft was the detachable fuel tank. Enemy machine-gun strikes in the fuel tank usually meant a horrible and fiery death for the crew, because very few air squadrons had access to parachutes. Rumors about these new aircraft sporadically reached the front. Curt Muller, a pilot at the observers' school in Altenburg in March 1918, wrote a letter to his parents:
  “[...] soon we are supposed to receive the incredible metal aircraft from Dornier. We are hearing the most amazing rumors about them [...]"
  In the end, due to delays and bureaucracy, none of these modern aircraft reached the front during the First World War.



Specifications of Zeppelin-Lindau Aircraft

Type Length, m Span, m Height, m Chord, m Propeller Manufact. Armament
(guns) Weight, kg Motor Crew
CL.II 7.46 10.60 2.95 Axial 2 fixed, 1 flex 730 Daimler D IIIa 2



Military Numbers of Dornier-ZWL Aircraft
Military Designation Manufact. Type Class Engine Notes
1850-1899/18 ZWL (Do) CL.Ia/CL.II DIIIa Only 2 aircraft were built
1900-2019/18 ZWL (Do) ? Order cancelled