Dornier Do 28 A/B
The Do 28 was developed from the single-engine Do 27 at the end of the 1950s. The design shared the high-wing cantilever layout and the lift augmentation devices of the Do 27, together with the rear fuselage which seated six passengers.
The most defining feature of the new design was the unusual incorporation of two Lycoming engines, as well as the two main landing gear shock struts of the faired main landing gear attached to short pylons on either side of the forward fuselage. The internal space of the Do 28 was the same as the Do 27.
Like the Do 27, the Dornier Do 28 possessed a high cruising speed, excellent low-speed handling characteristics, as well as very short takeoff and landing (STOL) performance. The Do 28 was readily accepted as a natural progression from its single-engine forebear. With many of the same STOL characteristics, most Do 28 production was destined for military customers, notably Germany, although a small number were in service for commercial operators as a rugged, low-cost utility transport. The design proved remarkably adaptable and was developed into a number of progressively improved variants, from the original D, through the D1 and D2 to the 128-2, introduced in 1980. Each variant introduced a number of detail changes that enhanced its already versatile performance capabilities.
Dornier Do 28 D Skyservant
The Dornier company was given financial assistance from the German government to develop a larger STOL transport to carry up to 13 passengers. The type was designated the Do 28D and later named Skyservant. The Do 28D was a complete redesign and shared only the basic layout and wing construction of the earlier versions. The fuselage and engine nacelles were rectangular, unlike the rounded Do 28A/B. The aim was to develop a simple and rugged aircraft for use under arduous conditions, which could be easily maintained. With a crew of two pilots, the cabin accommodated up to 12 passengers; freight could be loaded easily through large double doors and with the seats removed the cabin gave 283 sq ft (26.3 m2) of unobstructed space. The first flight of a Do 28D took place on 23 February 1966 and the type was publicly exhibited at the Paris Air Show at Le Bourget airport in June 1967.
A further variant of the Skyservant was the Do 28D-2/OU (Oil Unit). Two aircraft were fitted with radar and SLAR (Side-Looking Airborne Radar) to monitor oil pollution in the Baltic and North Seas. Painted in a white scheme, they were operated between 1984 and 1995 by MFG 5 of the Marineflieger, on behalf of the German Transport Ministry. These aircraft are easily recognised by the fuselage-mounted SLAR antenna and a radome under the cockpit. In 1991, both aircraft operated for several weeks in the Persian Gulf during the Gulf War under the control of the United Nations. These two aircraft were replaced by the Do 228 at the end of 1995. These Skyservants are preserved in the Aeronauticum museum at Nordholz.
In 1997, the Hungarian engineer Andreas Gál developed a conversion based on a D-variant, that was intended to meet the requirements of skydivers. Instead of the Lycoming piston engines, Gál had two Walter M601-D2 turboprops, modified three-blade propellers and a skydiving kit installed by Aerotech Slovakia on seven planes. Although CAA, Hungary's aviation authorities, instantly certified the conversion, the JAA-certification could not be applied for before 2007, due to certification restrictions on the engines. In 2008, there have been six planes flying in Europe, all of them Hungarian registered, mainly at dropzones in Soest, Germany, Wiener Neustadt, Austria, Target Skysports, Hibaldstow in the United Kingdom and Seville (Spain).