Focke-Wulf crane III
| Focke-Wulf crane III | |
|---|---|
|
|
| Type: | Glider |
| Design country: | |
| Manufacturer: |
Focke-Wulf GmbH, Bremen |
| First flight: |
May 1, 1952 |
| Production time: |
1952 to 1957 |
| Number of pieces: |
40 |
The Kranich III is a two-seater glider manufactured by Focke-Wulf GmbH in Bremen . After the Allies approved glider flight, the two-seater was the first performance glider developed and built in Germany since the end of the Second World War, and at the same time the last glider design by Hans Jacobs .
history
The lifting of the ban on flying and building gliders that had existed since the end of the war in 1951 led the Focke-Wulf Works in Bremen to make efforts to resume aircraft construction. After the well-known pre-war designer Hans Jacobs was hired, a revised version of his successful DFS Weihe model was produced before he ventured into a completely new design. Together with employee Richard Koitzsch, a two-seater performance glider was designed and built within a few months.
The first flight of the prototype with the registration D-3002 took place on May 1, 1952 at Bremen Airport with Hanna Reitsch at the wheel.
construction
With the predecessor DFS Kranich II , developed in 1936, the only thing that the machines built by Focke-Wulf have in common is the name and the number of seats. The Kranich III is a cantilevered middle decker in mixed construction. The fuselage is a tubular steel construction covered with fabric with seats arranged one behind the other and a double steering wheel.
The wings are made of wood, covered and based on Jacobs' pre-war construction DFS Weihe, but with an enlarged wing area. Edge lobes are attached to the wing tips to reduce the induced drag . The Schempp-Hirth airbrakes built into the landing aid produce a characteristic whistling sound when actuated. There are different chassis configurations from the factory . In addition to a version with a continuous main runner and a detachable two-wheel chassis, there was either a brakable main wheel with a nose wheel or a nose runner.
Compared to other double-seaters of its time such as the Doppelraab and the Schleicher Ka 4 , the Kranich III was designed less as a robust and good-natured trainer aircraft, but primarily as a performance aircraft. Nevertheless, the machine has extremely balanced flight characteristics. The DAeC index is 80.
successes
For the first time after the end of the war, a German delegation took part in the 1952 World Gliding Championships in Spain at the Cuatro Vientos airfield near Madrid. Focke-Wulf made the first two series aircraft of the Kranich III, completed a few weeks earlier, available to the participants in the two-seater class at short notice. The pilots only had a short training and acclimatization phase. Despite these adverse circumstances, Dr. Ernst Frowein vice world champion and Hanna Reitsch third.
The later double world champion Heinz Huth became German champion in 1955 on Kranich III.
The last world record for continuous gliding recognized by the FAI was set in 1954 by the two Frenchmen Bertrand Dauvin and Henry Couston on Kranich III. The flight was operated from April 6th to 8th and lasted a total of 57 hours and 10 minutes.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 2 |
| length | 9.08 m |
| span | 18.10 m |
| Elongation | 15.56 |
| Wing area | 21.06 m² |
| Wing loading | 19.9-26.1 kg / m² |
| Glide ratio | 30 at 95 km / h |
| Slightest sinking | 0.70 m / s at 70 km / h |
| Empty mass | 330 kg |
| Max. Takeoff mass | 550 kg |
| Minimum speed | 65 km / h |
| Top speed | 180 km / h |
Preserved copies
Only a few airworthy specimens out of a total of 40 crane IIIs have been preserved. A crane III with the identification D-2011 restored in the youth education center in Ratzeburg was recognized in November 2016 by the state of Schleswig-Holstein as a "movable technical monument".
Publicly exhibited specimens can be found in the German Glider Museum on the Wasserkuppe (former high-altitude research aircraft) and in the Museum of the Spanish Air Force in Cuatro Vientos. Another Kranich III hangs under the ceiling in Terminal C of Hanover Airport .
Others
The price of a Kranich III in 1955 was around 15,000 German marks , which corresponds to around 38,000 EUR based on today's purchasing power .
The model support is guaranteed by Eichelsdörfer GmbH in Bamberg.
literature
- Georg Brütting , Rainer Hüls, Alexander Willberg : The most famous gliders in the world , Motorbuch Verlag, Stuttgart 2009.
- Dietmar Geistmann: The gliders and motor gliders in Germany, Motorbuch Verlag, Stuttgart 2007.
- Karlheinz Kens: types of aircraft. Type book of international aviation, Carl Lange Verlag, Duisburg 1958.
- Peter Ocker: Hans Jacobs - pioneering life in aircraft construction. Self-published, Heidenheim 2012.
- Karl-Ferdinand Reuss (Ed.): Jahrbuch der Luftfahrt 1951/52 - Luftfahrt Taschenbuch, Pohl-Verlag, Munich 1952.
Web links
- Operating instructions for the "Kranich III" glider. Retrieved January 9, 2020 .
Individual evidence
- ^ Lars Reinhold: Memorial aircraft: Crane III. aerokurier, February 24, 2017, accessed January 6, 2019 .
- ↑ Original invoice from 1955. February 1, 1955, accessed on January 9, 2019 .
- ↑ This figure was based on the template: Inflation determined, has been rounded to a full thousand EUR and relates to January 2020.