Dornier Do 12
The Dornier Do 12, sometimes referred to as Dragonfly III, was a Kleinamphibium the aircraft manufacturer Dornier Metallbauten in Friedrichshafen Manzell that in 1932 as a single piece ( Wnr. 235) was built and flown. About the reasons which have led to the construction of this unusual in several respects aircraft, nothing is known. The only certainty is that it underwent various changes within three years.
Description
With the two around ten years earlier created small flying boats Thu A, Dragonfly I and II, has the Do 12, together except the shape of the hull bottom, as good as anything. Here is a completely new design, a high-wing monoplane in the usual Dornier all-metal construction with a zweiholmigen, trapezoidal structure, the trailing edge was very strong rounded in the transition to the hull.
The hull with a rectangular cross-section was keeled down flat and had a stage and a swing- keel guide. The various compartments were shielded against each other. In front in the bow compartment seafaring device could be accommodated, including anchors. Behind the open cab with two seats next to each other was switched on and off dual controls. There was a cabin with a further two seats with side windows. The subsequent rear cargo area could be used for luggage or be equipped with sleeping accommodations. At the height of the partition wall between the flight deck and cabin wells were installed on both sides that consumed the wheels in the retracted state. They could be swung with a hand crank. This was the first retractable landing at Dornier. For the company quite unusual because the two attached under the wings of two stems and clamped to both sides support swimmers who were used here instead of the usual fins stub. At the rear, the cantilevered fin sat with aerodynamic and mass balance on which was fixed at half height, which is also fully balanced tailplane.
As engine that powered a two -bladed propeller, air-cooled eight-cylinder engine Argus As 10 was originally fitted with 220 hp. He sat on a quest scaffolding high above the wing, in which the fuel was housed in two containers. As revealed in the course of testing that the engine power was insufficient, the Argus engine was replaced by a much stronger Gnôme -Rhône five-cylinder radial engine with 317 hp Titan 5 Ke.
Testing
Already during the first flight on June 23, 1932 had shown that the take-off distances were with the built-in motor considerably too long. However, the procurement of the stronger French engine took a lot of time and also challenged the then struggling with economic difficulties company before bad problems. The test therefore had to first be continued with the weaker engine. The following changes were necessary. The strong rounding of the wing trailing edge from the fuselage has been significantly reduced and now set the tailplane from the previous position to about a quarter of the fin height to bottom. With the new engine then had a large part of the test to be performed again.
Further use
With the MIVA ( Missionary transport working group ) of Father Paul Schulte, better known under the name The Flying Padre, got the plane, now with the registration D - INEZ, finally a new owner. Schulte used it for his missionary work, especially in Africa, where it did good service to him. How long it could do that, is not known. In the various books, the Father Schulte wrote about his experiences, it plays an important role. On the nose section, the aircraft bore the inscription " The Flying Cross".