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Arrow, first flew in Oct. 1943 and had a top speed of 474 mph. However, the lack of engine availability limited its production, and it saw no real war- time action. After the war, Dornier survived on aeronautical consultancy services in Spain and elsewhere out- side Germany. In 1954, it returned to original design work with the Do.25, which failed to be selected for produc- tion by the Spanish military.
Further development led to the Do.27 in 1955, which was chosen for production by both Spanish and German military forces. During the type’s subsequent decade of produc- tion, approximately 470 were built.
Eventually, over 20 nations would utilize Do.27s for utility, trans- port, liaison, and general- purpose missions. It could accommodate 4 fully outfitted troops in the cabin and the two pilots up front. Its rugged construction and exceptional STOL capabilities kept the Do.27 in military service well into the 1980s.
After several years of Do.27 pro- duction, in 1959, Dornier developed a twin-engine version to be certi- fied for civilian sales and market- ed it for various military and gov- ernmental roles. The design goals were enhanced redundancy and
performance with expanded load ca- pabilities while retaining the basic de- sign’s ruggedness, classic taildragger configuration, and STOL pedigree.
27 times 2 = Do.28
The similarities between the Do.27 and Do.28 are extensive. Removal of the engine from the nose allowed room for a slight expansion of the cockpit area. The cabin officially accommodates 6 (versus 4) on two bench seats in a club configuration, though it would be tight with 3 adults across each. Otherwise, the fuselage and empennage are identical. The Do.27 wing was retained on the Do.28 prototype, but a 5-foot increase in wingspan was incorporated into the production Do.28 A and B models.
Despite the commonalities, the unusual configuration of the Do.28 is unmistakable. Stub wings were added to the lower fuselage, pro- viding engine mounting platforms. Relocating the main landing gear below the engines allowed a much wider stance than on the narrow- tracked Do.27. For the production A-1 model, Dornier settled on 250hp, carbureted, Lycoming O-540’s, spin- ning 2-bladed, constant-speed props. The B-models upped the ante by add- ing fuel injection, 3-bladed propellers, and an increase to 295hp.
From any angle, the Do.28 is a unique twin. But one must admire Dornier’s break with tradition for maintaining commonalities and keeping the main wing’s highly effec- tive STOL design intact. One continu- ous slat clings to the wing’s leading edge from tip to tip.
Massive flaps can be deployed down to 45 degrees on the trailing edge. As the flaps deploy, the two-seg- ment ailerons divide into halves. The outboard halves continue to function traditionally. However, the inboard halves become flaperons, drooping as a percentage of flap deflection and remaining functional as ailerons for roll control. The 3-surface system just adds to the Do. 28’s non-traditional design philosophy. With the added lift of the lower stub wings and engine nacelles, 5 additional feet of span on
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Edge-to-edge slats enhance the wing’s STOL capabilities