Raab-Katzenstein RK 9
| Raab-Katzenstein RK 9 warbler | |
|---|---|
|
|
| Type: | Trainer aircraft |
| Design country: | |
| Manufacturer: | |
| First flight: |
March 1928 |
| Production time: |
1927-1929 |
| Number of pieces: |
24 |
.svg){kind=small}
The Raab-Katzenstein RK 9 warbler is a German training aircraft from the 1920s and the last model of the Raab-Katzenstein-Flugzeugwerke that went bankrupt in 1930 to be built in any significant number .
development
The construction of the RK 9 was carried out from 1927 by Paul John Hall and Erich Gammelin. The reason was, on the one hand, a related demand by the German Aviation Association (DLV) for a cheap "people's aircraft", with which the idea of "flying for everyone" should be realized in the aviation associations and, on the other hand, a decline in demand directly affecting Raab-Katzenstein for the larger ones built up to that point and heavier types Kl 1 Schwalbe and RK 2 Pelikan . Apparently only a short construction and development phase was assumed, because the company management registered the model for participation in the Sachsenflug , which takes place from August 30th to September 4th in the same year . However, this date could not be kept by far and the prototype was not completed until the spring of the following year. The tests carried out in March, however, confirmed the expected good-natured flight characteristics, so that the RK 9 went into production without any further delay after the approval was granted. The first 16 units received an Anzani engine with only 35 hp and were offered at a price of only 6,900 ℛℳ , the remaining eight were equipped with a more powerful Salmson engine with 46 hp and sold as RK 9a for 10,000 ℛℳ each. A 9b as RK called the float type with the same drive and the RK 9c with a two-cylinder - Scorpion -Motor remained just projects.
The RK 9 was presented to the public on the occasion of the ILA , which took place from October 7th to 28th ; two of them took part in the star flight on Berlin carried out at the beginning.
In the spring of 1928 turned Fritz von Opel to Antonius Raab to get asked for tests with one of the developed rocket engine a corresponding aircraft available. Thereupon the 25th and last RK 9 in production with the serial number 368 was converted into a duck plane and initially tested with an Anzani engine in pressure configuration. Later, the black powder-powered Opel engine was installed, but it exploded when Raab personally carried out the first test start. With a subsequent, apparently unsuccessful claim for damages by RaKa in June 1928, the relevant cooperation with Opel ended.
construction
The RK 9 is a cantilever, staggered one and a half decker in a composite construction . The wings of different spans are connected by N-posts. The upper wing has V-struts towards the upper fuselage and I-stems towards the lower wing-fuselage transition. Ailerons are only on the upper wing. The horizontal stabilizer of the tail unit is supported on the fuselage with I-posts. The chassis consists of the two rigid main wheels connected by an axle and a grinding spur at the rear.
Technical specifications
| Parameter | Data (RK 9) | Data (RK 9a) |
|---|---|---|
| crew | 1-2 | |
| span | above 8.96 m below 8.06 m |
|
| length | 6.85 m | |
| height | 2.90 m | |
| Wing area | 19.64 m² | |
| Wing loading | 22.9 kg / m² | 24.2 kg / m² |
| Power load | 12.9 kg / hp | 10.3 kg / hp |
| Empty mass | 250 kg | 275 kg |
| Payload | 200 kg | |
| Takeoff mass | 450 kg | 475 kg |
| drive | an air-cooled three - cylinder radial engine | an air-cooled nine-cylinder star engine |
| Type | Anzani | Salmson |
| power | 35 HP (26 kW) | 46 hp (34 kW) |
| Fuel volume | 42 l | |
| Top speed close to the ground |
110 km / h | 120 km / h |
| Climbing time to an altitude of 1000 m |
16 min | 13 min |
| Service ceiling | approx. 3000 m | |
| radius | approx. 350 km | 400 km |
Preserved copies
The only surviving specimen of a warbler is in the German Museum of Technology in Berlin . It was built in 1928 with the serial number 353 and still has the original license plate D–1519.
literature
- Rolf Nagel, Thorsten Bauer: Kassel and the aviation industry since 1923 . Bernecker, Melsungen 2015, ISBN 978-3-87064-147-4 .
Web links
Individual evidence
- ^ Marton Szigeti: Raab-Katzenstein . In: Aviation Classics . No. 1/2014 . Motor Presse, Stuttgart, p. 59 .
- ↑ Aircraft from the Technikmuseum Berlin: Raab-Katzenstein RK 9 "Warbler". Retrieved April 17, 2018 .