Dornier Thursday 12
|Dornier Thursday 12|
June 23, 1932
|Number of pieces:||
The Dornier Do 12 , sometimes referred to as Libelle III , was a small amphibious aircraft made by Dornier Metallbauten in Friedrichshafen-Manzell , which was built and flown in 1932 as a one-off (Wnr. 235). Nothing is known about the motives that led to the construction of this aircraft, which was unusual in several respects. What is certain is that it has undergone various changes over the course of three years.
With the two small flying boats Do A , Libelle I and II , which were built around ten years earlier, the Do 12 has almost nothing in common, apart from the shape of the fuselage floor. This is a completely new construction, a shoulder wing in the usual Dornier all-metal construction with a two-spar, trapezoidal supporting structure, the rear edge of which was very rounded in the transition to the fuselage.
The hull with a rectangular cross-section was keeled flat at the bottom and had a step and a swiveling sword for driving on the water. The different compartments were sealed off from each other . The nautical equipment including anchors could be accommodated in the bow space at the front. Behind it was the open driver's cab with two seats next to each other and dual controls that could be switched off . This was followed by a cabin with two more seats with side windows. The adjoining stern space could be used for luggage or it could be equipped with sleeping accommodations. At the height of the partition wall between the driver's cab and cabin, troughs were built in on both sides to accommodate the wheels when they were retracted. They could be swiveled out with a hand crank. It was Dornier's first retractable landing gear . Quite unusual for the company were the two support floats attached to two stems each under the wings and braced on both sides, which were used here instead of the otherwise usual "fin stubs". At the stern sat the cantilever vertical stabilizer with aerodynamic and mass balancing, to which the fully balanced horizontal stabilizer was attached halfway up.
As an engine, a two-bladed propeller drive, an air-cooled was originally eight-cylinder engine Argus As 10 with 220 hp (162 kW) installed. He was sitting on a strut high above the wing, which also contained the fuel in two containers. As revealed in the course of testing, the engine power was insufficient, the Argus engine through a much stronger was Gnôme-Rhône - five-cylinder - radial engine Titan 5 Ke replaced with 317 PS (233 kW).
During the first flight on June 23, 1932, it had already been shown that the take-off distances were considerably too long with the built-in engine. The procurement of the more powerful French engine took a long time and also posed serious problems for the company, which was struggling with economic difficulties at the time. So the testing had to be continued with the weaker engine. The following changes were necessary. The pronounced rounding of the trailing edge of the wing towards the fuselage was reduced considerably and the horizontal stabilizer was moved down from its previous position to around a quarter of the vertical fin height. With the new engine, a large part of the testing then had to be carried out again.
With the MIVA (Missions-Verkehrs-Arbeitsgemeinschaft) of Father Paul Schulte , better known as The Flying Father , the aircraft, now with the registration D-INEZ, finally got a new owner. Schulte used it for his missionary work, especially in Africa, and it served him well. How long it was able to do this is not known. It plays an important role in the various books that Father Schulte wrote about his experiences. On the bow of the fuselage, the machine was labeled "The flying cross".
|Wing area||28.00 m²|
|V position||6 °|
|Wing loading||50.00 kg / m²|
|Power load||4.67 kg / hp|
|Area performance||10.71 hp / m²|
|Empty mass||980 kg|
|Preparation mass||1075 kg|
|Takeoff mass||1400 kg|
|Engine||an air-cooled five-cylinder radial engine Gnôme-Rhône Titan 5 Ke
with adjustable two-bladed wooden propeller (Ø 2.35 m)
|power||300 hp (221 kW)|
|Fuel volume||190 l|
|Top speed||210 km / h|
|Cruising speed||180 km / h|
|Landing speed||103 km / h|
|Rate of climb||4.25 m / s near the ground|
|Rise time||4.0 min at 1000 m altitude
8.5 min at 2000 m altitude
15.0 min at 3000 m altitude
23 min at 4000 m altitude
|Service ceiling||5100 m|
|Flight duration||3.3 h|
- Dornier Foundation for Aviation and Space Travel (ed.): Dornier: Factory history and aircraft types . Delius Klasing, Bielefeld 2009, ISBN 978-3-7688-2610-5 , p. 97 .
- Günter Frost, Karl Kössler , Volker Koos: Dornier . From the beginning until 1945. Heel, Königswinter 2010, ISBN 978-3-86852-049-1 , p. 139-141 .
- The Flying Pastor. In: Jet & Prop, 1/2008, p. 13
- Helmut Schneider: Airplane Type Book. Handbook of the German aviation and accessories industry . Reprint of the original edition from 1944. Gondrom, Bindlach 1986, ISBN 3-8112-0484-X , p. 59 .