Dornier Do P

Dornier Do P
The Do P with built-in arms in Switzerland
Type:	four-engined heavy bomber
Design country:	German Empire
Manufacturer:	Dornier metal structures
First flight:	March 31, 1930

The Dornier Do P was a one -off four-engine heavy bomber built in Germany by the aircraft manufacturer Dornier Metallbauten (DMB) in Friedrichshafen under the code name Nachtfrachtflugzeug . It was created in the course of the secret rearmament of the Reichswehr on the basis of a tender from the Army Weapons Office . The Reich Ministry of Transport placed the relevant order with Dornier on March 20, 1929. The amount made available for this was initially limited to RM 1,000,000 for budgetary reasons. Although this approach violated the Treaty of Versailles , which prohibited the German Reich from building an air force , among other things , it was tolerated and even largely supported.

The genesis

The designation Do P had already been assigned to the 16 small airliners by Dornier at the beginning of the 1920s, which had become known under the names Komet I, II and III. For reasons that can no longer be determined today, the new draft was again given the designation Do P. The requirements of the Reichswehr for the aircraft had already been laid down in a note from January 1926. Construction of the Do P Sil began in July 1929 in Manzell , a district of Friedrichshafen . The work number was set to 180. The first flight on March 31, 1930 and the further flight tests took place at the Friedrichshafen-Löwental factory airfield . The aircraft was only brought to the AG für Dornier aircraft factory in Altenrhein on the Swiss side of Lake Constance for the installation and testing of the military equipment . After the renovation was completed, on November 24, 1930, it received approval from the Federal Aviation Office as CH 302. The company Aero Metall AG in Zurich, which also belonged to Claude Dornier , was registered as the owner . After the end of the trial, the military equipment in Altenrhein was removed again. At the same time, the aircraft received an additional horizontal stabilizer installed between the two side fins to improve the longitudinal stability . First it went back to Löwental and finally to Berlin-Staaken to the local testing site . As early as March 20, 1931, the DVL had taken over the aircraft for the Reich Association of the German Aviation Industry (RDL, later RDLI), which was now registered as Do P Sil with the registration D-1982, as ordered at the time, as a night cargo aircraft. At that time, the RDL operated, as a camouflaged military facility, not only the Staaken test site, but also Rechlin , Travemünde , Albatros Johannisthal and, above all, Lipetsk in Russia. The journalist Walter Kreiser wrote an article about the existence of these institutions , which Carl von Ossietzky published in his magazine Weltbühne . The result was the conviction of both for betraying military secrets. Lipetsk had not mentioned Kreiser, however, but indicated his knowledge about it. The aircraft actually came there in the summer of 1932 for technical and tactical testing. Among other things, it served with the reinstalled weapon stands equipped with the new D 30 slewing ring mount for testing the newly developed MG 15 . When Lipetsk was dissolved in October 1933, the Do P was left to the Soviets. Her further fate is unknown.

description

The Do P was an all-metal shoulder- wing aircraft, partly covered with fabric. The three-part and three-spar structure with a rectangular floor plan with well-rounded ends largely corresponded to the existing Superwal , but had a slightly larger span. It was supported on each side with two parallel struts against the underside of the fuselage. The four nine-cylinder radial engines Siemens Jupiter VI 6.3 were respectively installed in tandem in two detachable nacelles on the wing centerpiece, with corresponding four-blade tension, pressure or propellers own production. The fuselage, designed for a crew of six, had a rectangular cross-section and was planked with flat sheet metal fields, which were stiffened in the manner typical of Dornier at the time with hat profiles riveted on the outside in the longitudinal direction. In the bow was the place of the observer and, at the same time, the bombardier, who also had to operate an anti-machine gun up and down. The open driver's cab with two seats next to each other and with double controls went over to the rear into the two-part bomb room with magazines for smaller bombs. Larger ones had to be hung on outstations under the fuselage. This was followed by the rear rifle room, in which a machine gun stand was installed above and below. Another was in the stern. If occupied during the flight, it was the cause of the lack of longitudinal stability, which required the installation of the second horizontal stabilizer. To reduce the steering forces, all oars had auxiliary oars connected to the oars by rods on the outside . The landing gear, which was partly covered, was hinged to the fuselage with two V-arms and had spring struts towards the wings. At the stern there was a spring-loaded, towed tail wheel that could be swiveled through 90 ° to each side .

Technical specifications

Parameter	Data
crew	6th
length	23.40 m
height	7.30 m
span	30.00 m
Wing area	152.60 m²
Preparation mass	8,000 kg
Payload	4,000 kg
Takeoff mass	12,000 kg
drive	four Siemens Jupiter VI 6.3 U radial engines
Starting power rated power	530 PS (390 kW) each 470 PS (346 kW) each
Top speed	210 km / h near the ground
Rise time	13.2 min at an altitude of 2,000 m
Service ceiling	3,500 m
Range	1,000 km

See also

• List of aircraft types

literature

• Dornier Foundation for Aviation and Space Travel (ed.): Dornier: Factory history and aircraft types . Delius Klasing, Bielefeld 2009, ISBN 978-3-7688-2610-5 .
• Zeppelins Flieger , Frost, p. 117 ff, Zeppelin Museum Friedrichshafen 2006, ISBN 3-8030-3316-0 .
• Joachim Wachtel: Claude Dornier , Aviatic Verlag 1989, ISBN 3-925505-10-5 .
• Günter Frost, Karl Kössler, Volker Koos: Dornier. From the beginning until 1945. Heel, Königswinter 2010, ISBN 978-3-86852-049-1 .

Web links

Commons : Dornier Do P  - collection of images, videos and audio files

• Thomas Wilberg: Dornier P. Das Virtual Aviation Museum, accessed on October 14, 2009 . 

Individual evidence

1. ↑ Frost, Kössler, Koos, p. 113