present faults, it is likely to become one of our most useful fighter aircraft". A version of the Sh.III passed a 40-hour endurance test in June and the aircraft were cleared to return to service in July. In the meantime they had been upgraded with the addition of a new rudder, balanced ailerons and had the cowling cut-away for improved cooling. Some sources also claim that the original engines were replaced with the improved Sh.IIIa engines. Another thirty new aircraft with these features were built and all eighty of the improved design entered service in home defense units where their climb rate made them excellent interceptors. D.IV The short-span D.IIc prototype had been further refined and with a narrower chord upper and lower wing, using the Göttingen 180 airfoil. One wing was slightly longer than the other to counter the P-factor of its huge four-blade propeller. The port panels outboard of the struts were in length, while those on the starboard side were long. The performance improved noticeably in top speed and in climb rate over the D.III. An order for this model, now known as the D.IV, was placed in March 1918 and additional orders were placed as the qualities of the design became known. Aircraft started reaching operational units in August but of the 280 ordered only 123 were completed by the end of the war, about half of those reaching operational units. Although the short landing gear and limited prop clearance led to tricky landing, the plane was otherwise easy to fly. It had a very short take-off run and at heights above was faster and more manoeuvrable than the Mercedes-powered Fokker D.VII. Its most notable feature was its phenomenal rate of climb and extremely high service ceiling—it could reach in under 14 minutes. In 36 minutes it could reach , about higher than the ceiling of the Fokker. Production of the D.IV continued after the cease-fire, while one example escaped to Switzerland where it operated from 1918 to 1922, and another was acquired by the Lithuanians, however it never flew in their service. One examples was used by the Belgians, being marked with the race number 22. With the signing of the Treaty of Versailles aircraft production in Germany was outlawed and the aircraft division of SSW disappeared. Siemens-Halske later reorganized into Bramo. D.V In May/June 1918 a sesquiplane, two bay derivative, the D.V participated in