Fischer-Boretzki FiBo 2

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Fischer-Boretzki FiBo 2
f2
Type: Glider
Design country:

Germany Federal RepublicFederal Republic of Germany BR Germany

Manufacturer:

Fischer-Boretzki

First flight:

1953

Production time:

1953-1954

Number of pieces:

1

The Fischer-Boretzki FiBo 2 is a glider with preparation for a later engine mount , which was developed by Hanno Fischer in the early 1950s. The FiBo 2 is Hanno Fischer's first aircraft design and is regarded as the starting model for a development chain that led to the RFB Fanliner and RFB Fantrainer via the later RW-3 in the 1970s .

history

Hanno Fischer completed his technical training in the early 1950s. When the Allied military authorities repealed the Control Act No. 24 on June 19, 1951 , which up until then prohibited all gliding activities in Germany , Hanno Fischer and Toni Boretzki made the decision to build their own glider. Hanno Fischer took over the technical development of the design, while the former carpenter Toni Boretzki was responsible for producing the prototype. First, Fischer tested his design using a flight model. The findings from the flight tests led to a fundamental revision of the design. The second draft was then given the name Fischer-Boretzki FiBo 2. Construction of the FiBo 2 prototype began in the winter of 1951/52 in Hanno Fischer's garage in Westhoven near Cologne. As the assemblies grew, the building finally moved to the street in front of Fischer's house.

construction

The initially single-seat aircraft was designed as a shoulder -wing wing with a T-tail unit. In contrast to most of the wooden sailplane designs that were made during this period, the Fischer-Boretzki FiBo was given a tubular metal frame and metal wings, and despite the still existing construction ban on motorized airplanes in Germany, Fischer put the machine, which was officially declared as a glider, for a later machine from the start Engine retrofit. For this purpose, Fischer provided a gap in the raised T-tail, in which a vertically lockable two-bladed propeller was arranged, which could be driven by a motor to be retrofitted later via a remote shaft. To accommodate the engine, Fischer provided a space behind the cabin, which he officially called the luggage compartment.

To test the long-distance shaft drive, Fischer converted a 15 hp DKW motorcycle engine to drive the long-distance shaft. When installing the engine in the FiBo 2 designed as a glider, sandbags had to be taken up as counterweights in the cabin. Only the later FiBo 2a was designed for a permanent motor mount without counterweights.

On January 16, 1952, Hanno Fischer submitted his first patent to the German Patent Office for the design of the FiBo 2 under the name “Glider with an auxiliary engine built into the fuselage” . After the motorized flight was released in Germany, the patent was granted in January 1956 under the number DE937744C.

production and logistics

The construction of the fuselage tube frame was done with the help of the Fischer garage workshop. The production of complex and large wing forgave Fischer to the United Aluminiumwerke Ristau, Pieper & Co . in Lüdenscheid. The FiBo-2 assemblies were assembled on the open road in Westhoven.

The assembly of the DKW engine in the luggage compartment of FiBo 2 violated the Allied Control Council Act on the prohibition of motorized flights in Germany. The English military authorities became aware of Fischer several times, but Fischer always succeeded in removing and hiding the engine in good time before raids by the military authorities and thus preventing the seizure and destruction of FiBo 2.

The prototype of FiBo 2 was completed in early 1953. The aircraft was named "Ostwind". Since Fischer wanted to test the engine directly on the first flight, the monitored airfields in the Cologne area were ruled out for the first flight. Fischer therefore switched to the section of today's A4 motorway, which was still closed in 1953, between Gremberg and the still destroyed Rodenkirchener Rheinbrücke . Since the DKW engine was not sufficient for the FiBo 2 to start, the start took place in the tow of a car. Only in the air did Fischer turn on the engine. This first flight of FiBo 2 was probably the first powered flight by a German aircraft after the Second World War. At least the FiBo 2 was one of the first two “illegal” powered aircraft in Germany, along with Heini Dittmar's HD 53 .

The first solo launch of FiBo 2 took place after the conversion to a DKW two-stroke engine with 30 HP in spring 1953 on the ring road of the disused Luftwaffe airfield in Cologne-Ostheim . After Fischer was surprised by the military police several times during his flight attempts, he stopped the flight attempts with the FiBo 2 in the summer of 1953.

Versions

  • FiBo 1 - flight model of the first FiBo draft (1952)
  • FiBo 2 - single-seat glider with optional 15 HP DKW engine (January 1953)
  • FiBo 2 - Conversion to an optional 30 HP DKW two-stroke engine (spring 1953)
  • FiBo 2a - two-seater motor glider with a different center of gravity (autumn 1953)

Modifications

During the flight tests, Bernhard Schulze-Wilmert became aware of Hanno Fischer's FiBo 2 in 1953. He was interested in marketing the aircraft, but thought a single-seat variant was not for sale. Since the opening of motorized flight in Germany was now indicated, the further developed FiBo 2a should no longer be designed as a glider, but as a motorized glider with permanent motor equipment. Based on FiBo 2, Hanno Fischer extended the cabin area to the front and arranged two seats one behind the other in the cabin. At the same time, the center of gravity was shifted to such an extent that the engine weight was balanced in the engine compartment behind the cab. The conversion of FiBo 2 was financed by Bernhard Schulze-Wilmert. It started in August 1953.

use

The FiBo 2 was used by Hanno Fischer exclusively to test the technologies used. The first public demonstration took place in August 1954 during the Glider Day in Bonn-Hangelar . The aircraft was then put into storage.

Sales figures / orders and deliveries

In the fall of 1953, the United Aluminum Works in Ristau were interested in starting license production of the further developed FiBo 2a. Until the lifting of the construction ban for motorized aircraft, the aircraft was to be marketed as a glider with a later upgrade function as a motorized glider. Bernhard Schulze-Wilmert and Hanno Fischer were to participate in the sales proceeds through a license agreement. When the FiBo 2a was discovered in the winter of 1953/54 during an inspection by the British military authorities in the United Aluminum Works, the authorities forbade the works from any further activity in aircraft construction. This ended the marketing efforts for FiBo 2a in 1954.

Technical specifications

Parameter FiBo 2 FiBo 2a
crew 1 1
Passengers - 1
length 6.80 m
span 13.90 m 13.90 m
height 2.15 m
Wing area 16.70 m²
Wing extension
Glide ratio 21st
Slightest sinking 0.85 m / s
payload 200 kg
Empty mass 200 kg
Max. Takeoff mass 300 kg 400 kg
Cruising speed
Top speed 135 km / h
Service ceiling
Range
Engines 30 HP DKW 30 HP DKW

Whereabouts

The FiBo 2 remained a one-off. The prototype was later sold to a private person who intended to further develop FiBo. Nothing more was known about this. Presumably the plane was later scrapped.

Trivia

  • probably the first motorized airplane in the Federal Republic of Germany

Comparable types

Related developments

See also

literature

  • Paul Zöller: Rhein-Flugzeugbau GmbH and Fischer Flugmechanik , 2016, ISBN 978-3-7431-1823-2
  • Hubert Zuerl: German gliders , 1954, Aero-Verlag Hubert Zuerl, Munich

Web links

Individual evidence

  1. ↑ Interview recording with Hanno Fischer, June 2016
  2. ↑ Hanno Fischer - an airplane life. Poller Heimatmuseum, accessed on May 12, 2017 .
  3. ↑ a b Hubert Zuerl: German gliders . Aero-Verlag Hubert Zuerl, Munich 1954.
  4. ↑ FiBo 2 patent from 1952. (PDF) Accessed in 2017 .